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RUBBER 
MACHINERY 



An Encyclopedia of Machines Used in Rubber Manufacture. 
Crude Rubber Washing, Drying, Preparing of Ingredients, 
Mixing, Preparing of Fabrics, Calendering, %)ulcanizing ; 
Calenders, Drives and Safety Stops; T^resses and Molds; 
Spreaders and Tubing Machines; Machines Used in the 
Manufacture of Reclaimed Rubber and Cements ; Temperature 
Regulatmg Devices; Extracting Machines for Wild Rubber, 
for Deresination ; Laboratory Equipment, Testing Machines 
and Devices, etc. 



By HENRY C. PEARSON 

Editor of The India Rubber World 

Author of '^ Crude Rubber and Compounding Ingredients, " "What I Saw 
in the Tropics, " "Rubber Tires and All About Them, " 
"The Rubber Country of the Amazon, " etc. 



NEW YORK 

THE INDIA RUBBER WORLD 

1915 






Copyright, 1915 

BY 

HENRY C. PEARSON 



All rights reserved, including that of 
translation into foreign languages 



QGT -81915 



,C1.A411860 



To the Inventors and Builders 

of Rubber Machinery 

Whose Mechanical Genius has Transformed 

a Hand Process Industry 

into one in which 

Labor Saving Machinery is the leading factor. 



; 



/ 



PREFACE 



FOR more than fifty years mechanical and inventive ingenuity has 
been producing machinery for use in rubber manufacture. In 

crude rubber washing, mixing and calendering the problems were 
once thought to be comparatively simple and their solution about the 
same the world over. Today, however, scores of new and more effi- 
cient machines handle new gums and intricate compounds, and the 
simplicity disappears. Even in the preparation of the crude material 
for market, machinery is to a marked degree supplanting hand labor. 

Rubber manufacture, be ;t noted, divides itself into some thirteen 
well defined classes. In these lines there are certain basic processes 
that all use^washing and mixing, for example. It is true, also, that 
most of them make cements, for their own use at least; that a great 
number use tubing machines; that spreaders are used by others than 
' 'proof ers," and so on. The object of this volume is to record the 
machines that are of general application either to all or to a number of 
the lines into which the trade is divided. 

To this end voluminous matter has been collected from machinery 
makers the world over ; from rubber factories, from patent specifications 
— American, English, German and French. The actual value of such 
a collection to the rubber manufacturer, whatever his line, should be 
great, but the suggestive value will be even greater. 

To the manufacturers of rubber machinery in the United States, 
England, Germany, France and Belgium, the author takes the oppor- 
tunity to express his thanks. Their generous promptitude in furnish- 
ing photographs, blue prints and details of special machines has made 
the task of arrangement and description much easier and the book far 
more complete than it could otherwise have been. 

The files of the ''India Rubber Journal,'' and "Gummi-Zeitung" 
and "Le Caoutchouc et la Gutta Percha" have also been of definite 
assistance in the collection of material, and my debt to these excellent 
journals is gratefully acknowledged. The members of my staff, also, 
and various rubber engineers have materially lightened the labor of 
putting the subject matter into shape. 

That there is much yet to be done ere rubber processes are mechan- 
ically perfect none will deny. If, therefore, by recording what has 
been done the writer is able to help the rubber trade toward greater 
triumphs, his aim will have been accomplished. 

Henry C. Pearson 



CONTENTS 



CHAPTEK I. 

The Washing of Crude Rubber (^9 

Cutting and Shredding Machines. — Two and Three- Roll 
Washers. — Tub Washers and Hollanders. — Enclosed Washers. 
— Slicing and Washing Machines. — Miscellaneous Washers. 

CHAPTER 11. 

Crude Rubber Drying 33 ' 

Vacuum Dryers. — Channel Dryers. — Vacuum Pumps. — Con- 
densers. — Percentage of Moisture in Rubber. — Percentage Loss 
of Weight in Drying. 

CHAPTER III. 

Dry-Sifting and Batching of Compound Ingredients 48 

German Reciprocating Sifters. — Gyrator Sifters. — Automatic 
Measuring Machines, — Compounding Scales. — Pulverizing 
Mills. — Rotary Dryers. — Automatic Weighing and Compound- 
ing Ingredients. 

CHAPTER IV. 



TflfE Mixing or Compounding of Rubber ' 59 

Mixers. — The Mechanics of Mixing. — Cooling Rolls. — Built- 
Up Rolls. — Miscellaneous Rolls. — Standard Mixers. — Trans- 
parent Covers. — Refiners. — "Jumbo" Mill with Partition. — 
Crackers. — Mechanical Feeds. — Automatic Mixers. — Three- 
Roll Masticator. 

CHAPTER Y. 

Preparing Fabrics for Calendering and Spreading 84 

Multiple Cell Dryers. — Fabric Stretching Machines. — Cloth 
Measuring Device. — Cloth Measuring Counters. — Singeing 
Machines. — Vertical Brushers. — Cloth Inspector. — Railway 
Sewing Machine. 

CHAPTER VI. 

Calenders '^3 

Two, Three and Four-Roll Calenders. — Leather Coating 
Calenders. — Calender Feed. — Hydraulic Lifts. — Electrically 
Heated Rolls. — Roll Lubricators. — Calender Gage. — Spreader 
Bars. — Separate Wind-Up and Cooling Rolls. — Stock Shells. — 
Roll Grinders. 



vi CONTEXTS 

CHAPTEK YII. 

Clutches^ Deives axd Safety Stops for Mills axd Calexders 113 
Friction Clutch. — Pjs^eumatic Clutch. — Magnetic Clutch and 
Brake with Flexible Coupling. — Dri\t:s for Calenders. — Two 
AND Three Speed Drives. — Electric Calender Drr-es. — Motor 
Characteristics. — Safety Stops. — \^ariable Speed Belt Drives 
FOR Calenders. — Variable Speed Transmission. — Model Calen- 
der Room Plan. 

CHAPTEE YIIL 

MoLDS^ Metal aistd Rubber . 138 

Quick Curing Molds. — Open Frame Molds. — Molding Machines. 
— App-\ratus for Making Rubber Molds. — Care of Molds. — Motor 
Dri\-en Mold Cleaner. — Belt Drr^n Mold Cleaners. — Sand 
Blast Cleaner. — Machine Tools for Mold Making. 



CHAPTER IX. 

YiTLCAXizERS — General Types 148 

Horizontal Vulcanizers.-'-\'ertical \'ulcanizers. — Horizontal 
Jacketed \'ulcanizers. — \"ertical Dry-Heat Vulcanizers. — 
Steam Separator and Vulcanizer. — Continuous Processes. — 
Cold Cure Apparatus. — French Hot Air \'ltlcanizer. — Repair 
Vulcanizers. — Electric A'ulcanizers. — A'ulcanizer Doors. — 
Self-Sealing Doors. — Quick-Locking Doors. — Door Closing 
Devices. 

CHAPTER X. 

VuLCAxizixG Presses^ Screw axd Hydraulic 165 

Standard Press. — Double Screw Press.— Toggle Joint Press. — 
Hydraulic Presses. — Swan-Xeck Press. — Three-Platen Press. — 
Gang Press. — \'ulcanizer Presses. — Hydraulic Accumulators. 



CHAPTER XT 

Tube Makixg Machinery ITO 

Stand.\rd Tubing Machines.— Motor Drive. — Tubing ^vIachine 
Feeder. — Striped Tubing Machine. — Tubing Dies. — Hammering 
Machines.— ^Iultiple Tube ^Iachine.— Stock Shears.— Stock 
Cutters. 



CHAPTER XII. 

Spreaders, Doublers and Surface Einishees 194 

Stand-\rd Spreaders. — Miscellaneous Spreaders. — Reversible 
Spreaders.— Spreaders and Stretchers.— \^ertical Spreaders.— 
Roller Spreaders.— Coated Fabric Dryers.— Polishing, Curing 
and Pasting Machine.— Chalking Machine.— Starching and 
Cleaning Machine. — Printing Machine. — Dull Finish 
Machine. — Automatic Solicitor Guide. 



CONTENTS vii 

CHAPTEK XIII. 

Spreaders^ Doubeers and Surface Finishers {Continued). — 

Doubling Calenders 216 

Horizontal Doubling Calenders. — Fabric Striping. — Fabric 
Feed-Roll Spreaders. — Vulcanizers for Coated Fabrics. — Vapor 
Cure. — Cold Cure Machines. — Impregnators. — Shower Proofers. 
— Solvent Recovery Apparatus. — Hood for Solvent Vapors. 

CHAPTEK XIV. 

Cement and Solution Machinery 238 

Dough Mills. — Solution Mixers. — Change Can Cement Mixers. 
— Twin Solution Churns. — Solution Pans. — Solution Strain- 
ers. — Screw Type Strainers. — Hydraulic Strainers. — Machine 
for Filling Tubes. — Cement Cans. — Cement Storage Tanks. — 
Naphtha Storage. 

CHAPTEK XY. 

Extraction of Kubber and Gutta Percha from Shrubs, 

Vines, Koots and Leaves 254 

GuAYULE Shredders. — Rotary Cutters. — Pebble Mills. — Gua- 
YULE Crushers. — Extractors. — Washers. — Separators. — Crusher 
AND Extractors. — Blocking Press. — Landophia Decorticators. 
— Process of Extracting Rubber. — Gutta Percha Extractors. 

CHAPTEK XVI. 

Extraction of Kesin from Kubber and Gutta Percha 271 

Deresinating Apparatus. — Alkali and Continuous Processes. — 
Gutta Percha Process. — Resin Extractors. — A French Process. 
— A German Deresinator. 

CHAPTEK XVII. 

Keclaiming 283 

Baling Presses. — Alligator Shears. — Cutters. — Bead Trim- 
mers. — Shredders, Grinders and Pulverizers. — Powdering 
Machine. — Grinding Machine. — Disintegrators. — Separating 
Rubber and Fabric. — Fiber Separators (Dry). — Miscellaneous 
Separators.— Defiberizing Tanks. — Defiberizing Apparatus. — 
Washers. — Cleaning Apparatus. — Washer-Separators. 

CHAPTEK XVIII. 

Keclaiming {Continued). — Conveyors 306 

Devulcanizers. — Electric Devulcanizers. — Water Separators. — 
Hot Air Dryer. — Continuous Screw Press. — Hot Air Rotary 
Dryer. — Rotary Vacuum Dryers. — Cleaning by Extrusion. — 
Strainers. — Three-Way Head Strainer. — Sheeting Mills. — 
Refining. — Refining Calenders. — Reclaimed Rubber Press. — 
Reforming of Rubber Waste. — Reforming Molds. — Reforming 
Machines. 



viii CONTENTS 

CHAPTER XIX. 

Temperature Recording and Controlling Devices 327 

Pressure Regulators.— Reducing \'alves.— Thermostatic Regu- 
lators. — Steam Gages. — Pressure Gages. — \'acuum Gages. — 
Recording Gages. — Precision Recorders. — Recording and Alarm 
Gages. — Thekmo.meters. — Mercury Cur Thermometers. — Record- 
ing Ther.mometers. — X'arnish Thermometers. — Helical Tube 
Recorder — Spiral Tube Recorder. — Temperature Alarm Syste.m, 
— Electric Alarm System. — System of Temperature Control. — 
Time Valves. — X'ulcanizer Control. 

CHAPTER XX. 

Rubber Laboratory Equipment 356 

Testing Crude Rubber. — Laboratory Rubber Machinery. — Hand 
Rolls for Washing. — Cylindrical Vacuum Dryer. — Freas' 
Vacuum Oven — X'acuum Dryer with Condenser. — Vacuum 
Shelf Dryer. — Electric Oven. — Centrifugal Separator — Elec- 
tric Centrifuge. — Scales and B.\lances. — Counting Sc.vles. — 
Extraction Appar.\tus. — Electricau.y Heated Apparatus. — Mul- 
tiple Unit Heater. — Digestion Flasks and Distilling Appa- 
ratus. — Viscosi meters. — Apparatus for Determining Specific 
Gravity. — Specific Gr.wity and Compound Cost Calculators. — 
Physical Testing of Rubber. — Grinding Mills. — Autographic 
Machines. — Hysteresis Machine. — Gages. — Dynamometer. — 
Textile Testing M.^chine. 



CHAPTER I. 

THE WASHIN^G OF CRUDE RUBBER. 

CRUDE rubber (wild) as it comes to the market appears in a great 
variety of forms — hams or pelles, balls, strips, sausages, lumps, 
flakes and all conditions of scrap. This rubber is packed in rough 
boxes, in casks and in bales. The manufacturer, on receiving a lot, at 
once opens the packages, weighs and tares them. Each lot is stored sep- 
arately, preferably in bins on the ground floor of the store-room which 
should be as near as possible to the wash room. Storage rooms for rubber 
should be fireproof, dark and cool. There is no necessity for them to be 
damp. Cement floors are the best and should be channeled to allow the 
water that drips from the rubber to run away. Pelles of fine Para can be 
put in heaps of almost any size, indeed, in case of fire a big heap is a 
protection as the mass will glaze over with melted rubber and the inter- 
ior be saved. For lower grades of rubber it is well to have the bins 
shelved so that the rubber cannot heat and further deteriorate. Each lot 
should be tagged and record kept as to condition and weight, and fol- 
lowed through the wash room and drying room, that handling, shrinkage, 
etc., may be known and the cost accurately estimated. 

In all wild rubber there is more or less foreign matter that 
must be removed before the rubber can be used in manufactured goods. 
The foreign substances are bits of bark, leaves, splinters of wood, sand, 
fibre, earthy matters, etc., etc. The only exceptions to this very general 
rule are deresinated and plantation rubber. Many manufacturers find 
it worth their while to wash even these sorts, as the process seems to 
result in a better and tougher product. The primary process, whatever 
the line of rubber manufacture, therefore, is that of washing. This is 
really most important, for the cleaner the rubber the better the manu- 
factured product. The wash-room employs heavy machinery, hot and 
cold water and steam, and is, therefore, a sloppy, dirty department, 
the air full of vapor and often smelling vilely. It is, therefore, prefer- 
ably separated from all other departments. The workmen usually wear 
rubber boots and rubber aprons, and for tools have bale hooks, big 
knives and shovels which are used only at intervals. 



10 



RUBBER MACHINERY 



SoFTExixG Tanks. 
Crude rubber in pelles, lumps, etc., is often particularly hard and 
intractable. It could be torn to pieces by machines, but at the expense 
of much power and frequent breakages. It is, therefore, first softened 




T 



Fig. 1. — Softe::ixg Taxk axd Cage. 



by immersion in warm water. For this purpose great vats, called by 
the English^ Pickling Tanks, are constructed so that they can be filled 
with water and the water heated by steam jets. These tanks are usually 
built according to the ideas of the users. Some have the top flush with 
the floor, and some rise five or six feet above it. Sometimes they are 
of plank, other times of iron. Some are open at the top, others closed. 
It does not matter much which forms are followed, provided they are 
set to fill conveniently from the storehouse, and be emptied just as 
conveniently for the washers. 

In Fig. 1 is showm one form of tank which is used in a number 
of rubber factories, especially in Germany. Instead of throwing the 
raw rubl^er directly into the tank of warm water, it is placed in a per- 
forated bucket A and lowered into the warm water in the tank B, 
where it is left for a sufiicient length of time to prepare it for working. 
AVhere the quantities of rubber necessitate a tank of large size, the 
Aveight of the bucket will call for some mechanical means of rais- 
ing and lowering it into the tank. This is done by means of a chain 



THE WASHING OF CRUDE RUBBER 



11 



C passing over pulley blocks D. Provision may be made for swing- 
ing the supporting arm E to one side of the tank, or the latter may be 
mounted on rollers for pushing it to one side, so that the bucket may 
be lowered to the floor. There is the temptation on the part of manu- 
facturers to heat the rubber in these vats too much. Indeed, some of 
the poorer grades scarcely need such a process. For the better grades 
it should be remembered that once the rubber is permeated by the heat, 
and three or four hours should be enough, it should go at once to the 
washer. A longer immersion is very apt to notably subtract from the 
nerve of the rubber. 

Cutting- and Sheeddia^g Machines. 
Washing has as a preliminary, not only the softening but the shred- 
ding of the gum, that the water can get at the imprisoned particles 





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Fig. 2.— Power Kxife tor Cutting Rubber. 

of dirt and free them. This shredding is done by cutting and 
tearmg. For the larger pieces a power driven circular knife is used. 



12 



RUBBER MACHINERY 



The modern cutting machine for doing this work is shown in Fig. 
2. At A is shown a large circular knife protected on the top and rear 
by a guard B. C is an adjustable hand lever with a plate G by means 
of which lumps of rubber of any size may be held down against the 
table H. By means of the spring E the lever is held down while the 
rubber is being cut. The knife is operated by pulley F, tight on its 
shaft, the other pulley being loose to allow the machine to be thrown 
out of operation when desired. The table H may be moved toward 
the knife by pressing the foot lever D^ the table returning to its original 
position when the lever is released. By the use of this machine the 
rubber may be quickly reduced to small pieces which are more easily 
run through the rolls of the washer. 




Fig. 3. — Power Shredding Machine. 

For fine shredding of pseudo rubbers there is a European machine 
of value. It is in brief a drum, from the face of which project 
knife points set obliquely and acting like planer knives; that is, 
projecting enough to cut only thin shavings. The rubber is sent to 
the machine as dry as may be. Over the machine, however, is a 
water jet to help in the cutting and to cool the knives. A lump of 
rubber is set on the frame of the machine and held against the wheel 
by a lever on which is fastened a presser plate. The drum revolves 
at great speed and the lump is forced against it until it is cut 
into thin shavings. The machine, Fig. 3, in detail is as follows: 
In the rim or surface of the iron dram A are set a number of blades 



THE WASHING OF CRUDE RUBBER 13 

L in the holders B. This druin is eight to ten inches in width 
and the knives extend through slots in the surfaoe of the drum along 
almost its entire length. The hand lever C is pivoted to the frame of 
the machine at H, and has attached to it a plate E, by means of which 
the ball of rubber G is forced against the iron drum as the latter 
revolves at high speed. In order to increase the pressure at which the 
rubber is forced against the drum, or to allow the workmen to have 
both hands free, a pedal D is attached to the base of the frame and 
pivoted at E. When the pedal or hand lever is released, the weight F 
is sufficient to pull the plate E back from the drum, thus allowing a 
new ball of rubber to be inserted. The shreds of rubber, as they are h 
cut from the ball, are caught in any suitable container placed under/' 
the drum. A stream of water from an overhead pipe is allowed to ruuf 
upon the rubber in front of the blades in order to facilitate the cutting. 

The rubber when not thus cut is fed first into the cracker-washer. | 
The action of this machine is to tear or mangle the rubber, releasing J 
the dirt and bark, which are washed away during the operation by a * 
stream of cold water, which plays upon the mass. The cracker-washer 
is a heavy, two or three-roll type of machine, the size and number of 
rolls depending on the quantity of material to be handled. 

From it the partially cleaned rubber then passes to the two- 
roll washer (or to the tub washer). The province of the two-roll 
washer is to complete the washing process and to sheet the torn rubber. 
Warm water is used on the mass to produce a degree of stickiness, 
that the action of the rolls may form it into sheets. Cold water is then 
turned on and the sheets passed through the rolls repeatedly until com- 
pletely cleansed by the kneading action of the rolls and the running 
water. 

Two-Roll Washers. 
There is a great variety of washers in use in the world's rubber 
mills, but a majority of them are of practically the same design ; that 
is, they are usually two-roll machines, the rolls geared in different 
speeds and running toward each other. In rubber plantations prac- 
tically the same type of a machine is used, run either by hand or by 
power, and in some of the larger plantations batteries of machines are 
employed. As plantation rubber is washed very soon after coagula- 
tion, the machine may be quite light and does not take nearly the 
amount of power to run that the same types in rubber factories call for. 
It should be remembered that wild rubber shrinks anywhere from 12 
to 50 per cent., and that while a considerable percentage of this shrink- 
age is due to the water extracted from the gum, a great deal is foreign 



14 RUBBER MACHISERY 

matter, more or le^s injurious. It will at once be asked why 
manufacturers have not insisted upon rubber being washed at the 
source of supply and delivered clean and dry. thus saving much in the 
way of freights. The explanation is that as soon as rubber is washed 
and perhaps massed and its physical aspect changed, it is so easy to 
amalgamate inferior and superior qualities that manufacturers decline 
to take the risk of being cheated, and have consistently frowned upon 
all such suggestions. There have been, however, and still are. crude 
rubber washing companies in various parts of the world that have done 
a fair business, but none of them have been conspicuously successful 
as yet. 

There are at present some forty companies in the world making 
roll washers, and their patterns are more or less similar. It will, 
therefore, be simicient. in describing these machines, to take examples 
from the output of any of the higher class of machine manufacturers 
and describe them, as practically typical of the whole. 

EoU washers consist of heavy iron rolls running toward one another, 
set in substantial iron frames, fitted with piping so that hot or cold 
water m.ay be sprayed over the rubber as it passes between the moving 
rolls, and with sieve bottoms to save scraps, and guides between the 
rolls to keep the rubber from working into the bearings. These rolls. 
be it remarked, are fluted or corrugated so as to bite the often intractable 
and slippery gimi. 

Regarding the kind of corrugation, many experiments have been 
made to determine the best possible form. There is. for example, the 
saw-tooth corrugation, in some cases both rolls being cut to this shape. 
while in others one roll is smooth and the other cut. Probably more 
rolls are made with the V-shape^i corrugation than any other. Experi- 
ments have shown that this form will do quite as good work at least, 
as it holds its shape longer and is easier to recut than the other forms. 
It seems to be quite a question whether two cut rolls or one (one being 
a smooth roll) will give the better results. There are cases where two 
cut rolls with ordinary corrugations make good sheets, but in small 
mills where one machine is required to do all the work from breaking 
down the biscuit to sheeting out, the machine with one smooth and one 
cut roll with a friction of about l^^ "^o 1 in the roUs. is the better. 

Taking a two-roU washer of the standard type, it has about the 
following description. The frames are heavy in construction, accurately 
lined and firmly held in place by stay rods. These frames are side- 
capped, the caps beinor bolted in place with heavy bolts in order to resist 
the strain at this point. The journal boxes are solid cast, designed 



THE WASHING OF CRUDE RUBBER 



15 



to keep out water and dirt. The bearing surfaces are channeled to 
insure perfect lubrication and bronze-lined in the sections exposed 
to greatest wear. Oiling devices easy and safe of access are provided. 
The rolls are of hard gray cast iron. The grooves or corrugations 
of both rolls are milled in spirally about four to the inch. The front 
or drivins; roll revolves in stationarv boxes. The folloAvCr roil is 




Fig. 4. — Two-Roll Washer. 



brought into adjustment by means of steel adjusting screws, working 
in bronze nuts set into the back of the frames. 

The power is ordinarily taken from the main shaft by means of 
a clutch and pinion. The latter engages a spur gear, keyed to the 
driving roll. A gear is keyed to the other end of this roll and meshes 
with a larger gear keyed to the end of the follower roll, causing the two 
rolls to travel at different speeds. The following are standard sizes of 



16 



E UBBEE MA CHIXEEY 



10 X 20'' '' '' 


500 


12- X M'' " '^' 


900 


14 X 28'' '' '' 


L200 


15 X 30" " '' 


1,500 


16 X 36" " '^ 


2,000 


If these macliines received 



H. 


P. 


H. 


P. 


H. 


P. 


K 


F. 


H. 


P. 



two-roll washers and their ten-hour product when doing the whole opera- 
tion of cracking, sheeting and washing. 

8 X 16" 2 roll 300 pounds in 10 hours 71/2 

500 '' " 10 " 10 
900 '' '' 10 " 15 
'' 1,200 " " 10 '' 20 
" 1,500 " '' 10 " 25 
'' 2,000 " " 10 '' 30 H. P. 

rubber already cracked, they would 
do at least 25 per cent, more work. These machines weigh from 10,000 
to 23,000 pounds. 

Fig. 4 shows a machine that is either washer or cracker as desired. 
It has two corrugated rolls .1^ placed side by side and driven by 
the large gear B from the pinion C on the main driving shaft D. 
The front roll, the one shown in the illustration, is adjusted hori- 
zontally by the set screws E, and the bearings of the rolls are lubricated 
from oil cups F. The rubber to be washed is placed between the rolls 
and run over and over the front roll. A removable pan rests upon the 
cross bars G. In it is a screen which catches fragments of rubber, but 
allows the waste material to fall through to the bottom. It will be 
noticed that this machine is provided with shields H over the gears 
which drive the second roll, and a safety throw-out device operated 
by the cross bar K, situated conveniently above the machine. This 
safety device is fully described further on. 

The two roll cracker-washer used for cracking alone, the washing 
and sheeting being done on other machines, is capable of performing 
an immense amount of work. The following figures are a fair average. 
A machine 15 inches x 24 inches, 5,000 pounds in 10 hours, horse power 
used 35 ; one 16 x 30. 6,500 pounds in 10 hours, horse power used 50. 

When used for cracking, wi;shing and sheeting, however, it is 
practically the same machine as the two-roll washer. It is, however, 
usual to have the rolls more coarsely corrugated and of chilled iron. 
The rolls run at the ratio of about 1 to ll-o. A cracker-washer with 
rolls 15x24 should deliver 1,500 pounds of stock in ten hours, and 
take about 25 H. P. to do it. One 16 x 30 should produce 2.000 pounds, 
and require 30 H. P. One 18x36 should deliver 2,500 pounds and 
use 35 H. P. 

Heil and Esch describe a two-roll washer which is used for the 
final washing and sheeting. It is of light construction and built like 
a two-roll calender, with one roll above the other. The rolls are not 
corrugated and the friction is very slight. The water spray is fixed 



THE ^V ASHING OF CRUDE RUBBER 



17 



against the top roll. In operation, the cracked rubber is placed on a 
table in front of the machine whence it is fed. As the rubber sheets 
it is caught under the machine by a conveyor belt, while the 
dirty water runs over a protector that covers this belt and avoids further 
contact with the washed rubber. Such washers are not used in the 
United States and their value against the washer with the rolls side 
by side is problematical. 

Three-Roll Washers. 
The three-roll washer is designed to handle large quantities of 
rubber after it has been passed through the ^'cracker." It has a capacity 











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Fig. 5. — Three-Roll Cracker Washer. 



nearly double that of a two-roll machine of corresponding size, while 
only one operative is required. The frames are heavy, strong, should 
be accurately squared as to each other and securely held in place by 
strong stay rods or bolts. The caps are located on the front of the 
frames to facilitate removal of the rolls. They are of heavy construc- 
tion and provided with strong bolts to resist the powerful thrust 



18 



RUBBER MACHINERY 



directed against this part of the machine. The journal boxes are solid 
cast, provided with oiling devices, easy and safe of access, and the inner 
or bearing surfaces are oil-channeled to insure perfect lubrication, and 
designed to keep out water and grit. The bearing sections exposed to 
much wear are bronze-lined. 

The rolls are usually solid cast of hard gray iron. The grooves or 
corrugations of all three rolls are V-shaped, planed in spirally about 
four to the inch. The front or middle roll is the driver and revolves 
in stationary boxes. The two follower rolls are brought into adjust- 
ment with the middle roll by means of steel adjusting screws, working 




Fig. 6. — The Vaughn Iron Tub Washer. 



in bronze nuts set into the back of the frames. Power is applied from 
the main shaft by means of a jaw clutch and pinion which engages a 
spur gear keyed to the middle or driving roll. A gear is keyed to the 
other end of this roll and meshes with similar gears keyed to the ends 
of the two follower rolls. 

Three-roll washers come in three sizes, weighing about 15,000, 
18,000 and 25,000 pounds. They have a capacity for ten hours work in 
cracked Para rubber of 2,500, 3,500 and 4,500 pounds, using all the way 
from 50 to 100 H. P. If these machines were obliged to do their own 
cracking the output would be about 25 per cent. less. 

The three-roll cracker can be used as a cracker or a cracker-washer. 
The rolls are usually chilled and provided with coarse corrugations, 
such as the undercut or saw-tooth spiral shape with the face backed 
off, and the driving roll is geared to run 1 to 1% or 1 to 2 as compared 
to the follower. A steel neck is also recommended for the driving roll. 



THE WASHING OF CRUDE RUBBER 



19 



The three-roll cracker-washer does the entire work from the biscuit 
or crude material to the clean sheet. The corrugations are usually the 
V-shape spiral on all rolls, but in some instances the driving roll is 
corrugated and the follower rolls are smooth. The differential speed 
of the rolls is 1 to II/2. 

This machine is so simple in construction that it needs very little 
description. The front roll A (see Fig. 5) is the driving roll and is 
mounted in stationary bearings. The other two rolls, B and C, are 
provided with adjusting screws (not seen in the illustration), by means 
of which the rolls may be adjusted horizontally to within any distance 
of the stationary roll. The caps D and E, located on both sides of the 
frame, may be removed for taking down the rolls. The corrugations 
on the surface of the steel rolls are plainly visible in the illustration. 

Tub Washees oe Hollajstdees. 
A distinct type of washer has grown up by the side of the roll 
machine, and is very generally used, particularly in cleaning the softer 




Fig. 7. — The Tub Washer or Hollander 



gums. It is known as the '^Tub" washer and is very much like the 
so-called ''paper engine." 

It is in brief a tank anywhere from 2 to 16 feet long, with one 
or two beater wheels running in it. When filled with water and 
shredded material it runs the contents round and round the tank, beat- 



20 BUBBER MACHINERY 

ing and cleansing, and yet never crnshing. In nse the rnbber is first 
run through a cracker or cutter of some sort and shreddecL It is then 
put in the tub. which has been ])reviously filled with water. When the 
machine is started the rubber is carried under the washing roll and 
over the bed plate at the bottom, which s])reads and stretches the rubber 
and releases particles of sand or bark or other foreign matter. The 
bark, being lighter than the rubber, tioats on top and is skimmed off. 
while the sand and gravel settle to the bottom. 

The Vaugiix Tub Wasuer. 
In Fig. 7 the tub or tank .1 . which is used in many factories and 
sometimes on plantations, is di\ ided through its middle by a partition 
B which, how^ever does not extend the full length of the machine but 
leaves a space at each end for the circulation of water and rubber. 
Across the top is a shaft C driven by the belt pulley D, bearing a large 
washing roller underneath the cover E. The bed ]date F, also bears 
corrugations or teeth which serve to tear the rubber apart as it passes 
between the plate and the roller. A countershaft driven from the main 
shaft by the gear G bears a paddle wdieel 7v. By means of the hand 
wheel 11 and worm gear /, and the cross yoke J . the shaft C may be 
raised so that the distance between the washing roller and the bed 
plate is varied. AVhen the niachiiu^ is in use the beater drives the 
rubber around the tank, stretching it and tearing it between the 
roller and the bed plate. In this way the heavy foi-eign substances are 
released and sink to the bottom where they are separated from the 
rubber by a screen. This screen is set some distance above the bottom 
of the tank, about on a level with the lower side of the door L. The 
bark is skimmed off or is cari'ied away thr(^ugh an overflow. 

TuK P)EKTiJA^r Tub Wasuer. 
In Fig. 8 is shown an Fnglish type c^f tub washer in which the 
principle of operation is almost the same as in the Vaughn described 
above. It diifers, however, in a few details of construction. The 
machine consists of a cast iron trough A made in an oblong form 
with round ends. Screened sand traps are arraniied in the bottom of the 
trough for the heavier foreigii matter. Above the level of the screens 
is placed a corrugated bed plate attached to the box B, which is inserted 
through an opening in the side of the trough. Above this bed plate 
revolves a large corrugated roller wdiich is covered by the hood C. This 
corrugated roller is driven by a pulley keyed to the shaft H. The 
distance between the roller and the bed ]date is controlled by the hand 



THE WASHIXG OF CRUDE RUBBER 



21 



wheel D to give a greater or less tearing action to the rubber. The 
rubber is beaten and the dirt and bark are freed bv the screened drum 




Fig. 8. — The Bertram Tub Washer. 

E^ the dirty water being delivered over the side of the trough into a 
suitable trap. This drum is turned bv the belt pulley F and the amount 
of water removed can be regulated by lowering or raising the drum 
by the hand wheel G. Such a machine as this is suitable for washing 
all kinds of shredded rubber, especially those containing a large per- 
centage of impurities. 

U:s^ivEESAL Washer. 

A type of washer which is essentially European is an adaptation 
of a Masticator. The argument of the inventors is that in ordinary 
washing with the two or three-roll machines, impurities are all crushed 
or splintered and held in the rubber, causing a much longer duration 
of washing than should be necessary, and that this impairs the "nerve" 
of the rubber. 

The machine consists of a pair of deeply corrugated rolls, carried 
in a trough shaped at the bottom to follow the periphery of the rolls. 
The trough carries ledges at the back and front, which turn the rubber 
over and guide it between the rolls. There are gratings in the back and 
front of the trough, through which the lighter impurities escape. 

These machines come in three standard sizes, which take charges 
of rubber of twenty, forty and eighty pounds. The horse-power 
required is approximately 9, 15 and 25, and the time required per 
batch from ten to twenty minutes. The above relate to Para sorts. For 
low grade gums the charge may be as high as one hundred and fifty 
pounds. 



22 



RUBBER MAC my FRY 



One of these washers (Fig. 9) described in detail will clearly 
illustrate the mechanism of all. 

The inner trough A is fed with lumps of rubber weighing about 
10 pounds each. The corrugated rolls B revolve toward each other 
and seize the pieces of rubber, tearing them apart against the saddle C 
and then conveying the pieces up the walls of the trough to the pro- 
jecting edges of the trough at D. This operation is repeated contin- 
uously and automatically. 

At the bottom of the trough are smaller saddles E which give the 
rubber a turning motion and at the same time release the heavier 
impurities, allowing them to fall through slots in the bottom of the 
trough. In order to prevent these slots from clogging, shakers F are 
arranged in them between the saddles. 

The main washing trough A is surrounded by an outside trough 
G, which is provided with valves R and K for the removal of dirty 
water and for the regulation of the water level. Underneath the main 
trough is a sand tank L, having a drain valve M and a gate X. 
Located directly above the tank is a pipe from which water is sprayed 
continuously into the trough to wash away the impurities coming to 
the surface. At P are shown lateral sieves, so proportioned as to allow 
the passage of the impurities but to prevent the passage of the rubber. 
For drawing off the coarse substances, larger openings are provided 
between the stone catch D and the comb-like gTate Q. At the begin- 
ning of the washing of certain kinds of rubber, scraps float on top of 



iZ> R 




/ /r/, •nil; ::.!/. /'/,■ ./,;MMjMiyjjjim}}J. ' ± LD l_L/..' 




Fig. 9. — Universal Washer. 



the water. To prevent them from being carried away as waste material, 
an adjustable sieve R is placed over the grate Q until the rolls have 



THE WASHING OF CRUDE RUBBER 



23 



formed this scrap into larger pieces. By the mixing nozzle S between 
the hot and cold water valves, any desired temperature of water may 
be obtained. Also, by the various outlets, the water level in the 




Fig. 10. — The Hood Enclosed Washer. 



trough may be regulated. For instance, by closing the gate i\^ and 
the valves K and M and leaving valve H open, the water level is raised 
to the overflow channel T. If it is desired to raise the water level still 
further — which may be temporarily necessary for the removal of pieces 
of wood from scrap rubbers — the valve H is also closed, raising the 
level to the overflow edge U so that the water will drain off through the 
channel V. Underneath the machine is a waste water tank W which 
is connected to a drainage system. In this tank is a sieve X which 
catches small particles of rubber that may have accidentally passed 
through from the trough. 



24 



B UBBEB MA CHIXEBY 



The Hood E^'closed TVasher. 

Wliat is known as the Hood washer is a two-roll machine set in 
a closed tank, so that the level of the water during washing comes 
ahove the nip of the rolls. When at work the riiljber sheet tloats up to 
the surface and feeds through the rolls automatically. Floating 
impurities are washed away, while the heavier parts sink to the bottom 
out of the way and are removed periodically through a gate. 

In Fig. 10, which shows an elevation of the machine in cross sec- 
tion, the corrugated rolls A and B are mounted in a tank C having 
a sloping bottom D, which deflects the heavier impurities to the front 
of the machine. The tank has an extension E into which the surface 
liquid flows, carrying with it the lighter foreign substances. These are 
drawn off through the pipes F and G, the former having a sieve fltted at 
its upper end to prevent the loss of rubber fragments. The height 
of liquid in the tank is varied by a vertically sliding gate H with- 




FiG. 11— The Dessau Washer 



TBI: WASHING OF CRUDE RUBBER 



25 



in the extension E, this gate being regulated by the threaded hand wheels 
K. The charge of rubber is introduced between the rolls by the tilting 
hopper L, which is operated by the cable M. After passing through the 
rolls the rubber meets an inclined plane N which deflects the mass 
toward the front of the tank where it rises to the surface of the water. 
Here it is picked up by the revolving paddle wheel P and returned to 
the rolls. The washing liquid is supplied from the pipe R, into which 
steam and chemical solutions may be passed if desired. The liquid may 
be heated by the steam coil S lying on the bottom of the tank. 

The Dessau Washer. 
Another enclosed roll machine is the Dessau. It consists of a pair 
of rolls, corrugated and studded, revolving in a central screened box 



Fig. 




Sectional View of the Dessau Washer. 



that is in turn enclosed in a tank. This gives a gathering space at the 
bottom and sides for foreign matter. The heavier foreign particles, if 
held in the washing liquid, may again be taken up by the rubber. One 
of the objects of the Dessau washer is to keep all impurities away from 



26 



RUBBER MACHINERY 



the rubber and thus prevent them from being again mixed with it. For 
this purpose the double tank is provided, together with means for con- 
tinuously agitating the liquid in the region where settling occurs. 

The machine has two rollers A and B (see Figs. 11 and 12) located 
between screens C in the trough E, with an overflow space F in each 
side of the trough, into which water surges under action of the platen G. 
This platen is joined at H to the vertical screw K and rocks up and 
down. In the bottom of the spaces F are two spindles L L, provided 
with a series of agitator blades. They are driven by sprockets M M, 
chains N N and gears P. 

The Kempter Washer. 
Another enclosed washer is the Kempter, of German origin. This, 
like the Masticator washer, has bladed rolls set in cur^^ed troughs. The 




Fig. 13.^The Kempter Washer. 



rubber passes down between the rolls, is opened up by a ledge between 
the troughs and then up between the rolls and the sides of the troughs. 
Foreign materials pass through perforations in the sides and over lips 
on either wall. 

In this machine (Fig. 13.) means are provided for separating the 
heavier from the lighter foreign materials and for treating the waste 



THE WASHING OF CRUDE RUBBER 



the second time to separate every particle of rubber therefrom. The 
mass of crude rubber or gutta percha to be treated is placed in the 
trough A containing two rolls B and C. These are formed with longi- 
tudinal projections which act as cutting or tearing edges. The bottom 
of the trough A has a center ridge D^ giving it the form of two inter- 
secting cylinders surrounding the rolls. When water is introduced and 
the machine started, the rubber is drawn down between the rolls. The 
roll corrugations and the ridge D tear the rubber apart and carry it 
up between the rolls and the sides of the trough A. The heavier foreign 
particles pass over the edges E and F and through gratings G into the 
surrounding tank H. The lighter impurities float to a channel K, 




Fig. 14. — The Pointon Washer. 

from which they may be floated off by raising the water level. The 
water and impurities are discharged into a tank L which is provided 
with screens, and the mass collecting thereon may be taken back to 



28 



RUBBER MACHINERY 



the tank A for further treatment. When the rubber has been suffi- 
ciently washed, the trough A is emptied by rotating it about the shaft 
of the roller B. 

The Pointon Washer. 

Pointon's machine is notable in having adjustable closing devices^ 
to regulate the area of the troughs beneath the rollers. 

Fig. 14 shows it in transverse section, looking toward the ends of 
the rolls. The closing devices are plates A, each having its upper edge 
shaped to- enter an aperture in the trough B, below the rolls C. The 
lower edge of each of these plates is provided with an eccentric D, 
whereby the plate may be raised or lowered. These eccentrics are 
mounted on shafts E which are carried at their ends in the hinged 
covers F of the sump G. The ends of the shafts are mounted in bear- 
ings H, and may be moved on removing the caps I, thus ^hanging the 
position of the plates A. 

The water level is regulated by vertically sliding pipes J, which 
co-operate with the subsidary weirs M through the opening in 
the bottom of each. When the pipe is in the position shown, water 
can enter the main trough through the upper end of the pipe. With 
the use of the weir a great increase in the height of the water level is 
obtained with a very small movement of the pipe, and in this way the 
employment of a sliding outlet gate is avoided. 

The sump-like portion G below the trough has a sloping base, 
that the heavy impurities may escape through the center valve 0. 




Fig. 15. — The Donnelly Slicing and Washing Machine. 



THE ^YASHIXG OF CRUDE RUBBER 



29 



The sides of this sump are hinged to drop down for cleaning pur- 
poses. At the top of the trough are adjustable perforated partitions 
or sieves P which are mounted on pins Q and on which they are 
rotated to open the main trough to the side weirs. 

The Doa'xelly Slicixg axd Washixg Machine. 

Donnelly's machine slices crude rubber and sheets and washes it. 
In brief, it has a guillotine knife for cutting the rubber, two pairs of 
washing rolls and a pair of sheeting rolls. The drawings (Fig. 15) 
show a front and a side elevation of the machine. The bed A car- 
ries a table B, above which are secured two uprights C and D, 
forming guides for the knife E. A transverse shaft F carries two 
cranks G to which are attached the lower ends of the connecting rods 
H. The upper ends of these rods are pivoted to the outer ends of the 
knife E. The upright guides C and D carry two rollers / which work 
within diagonal slots J in the knife. On the table 5 is a feed board 
K, secured to the rack L. This rack is moved forward by the ratchet 
wheel M and the chain N, operated by each upward movement of the 
knife. Above the table is a presser bar Oj which holds the rubber firmly 
in position. The carriage which bears this presser bar may be adjusted 
by means of the hand screw P to fit different sized lumps of rubber. 
The operation is as follows : 

A lump of rubber is placed on the table and pushed forw^ard under 
the knife. During the cutting a stream of water plays over the rubber 
from the pipe X. As each slice of rubber leaves the cutter it passes 
between the pair of grooved washing rolls Q^ where it is squeezed and 
rolled to remove the impurities. It is then carried by the conveyor 




/? 



Fig. 16. — The Smith Washer. 



30 



RUBBER MACHINERY 



R to the second pair of rolls *S'^ where it is again rolled and pressed. 
It is then carried on a second conveyor T to a third pair of rollers U, 
which sheet it. 

The Smith Washer. 
Smith's machine, illustrated in Fig. 16, is of somewhat unusual 
construction. Upon the bed plate A are mounted two frames B and C. 
One is rigidly attached, while the other is pivoted at its lower end. 
Each of these frames has a series of jaws E and F extending toward 
each other. These jaws are U-shaped and are provided with teeth. 
When the frames 5 and C are at their minimum distance apart, as 
shown in the drawing on the left, the toothed portions of the jaws 
E and F form opposite sides of an almost circular passage through 




Fig. 17. — The Day Washing Machine. 



which the rubber descends from a hopper G in the upper part of 
the frame B. When the frame C is set in motion, by power applied 
to the pulley H and communicated to the frame through the 
connecting rod I, the jaws F are forced back as indicated at /, so that 
a lump of rubber of the shape shown at K will be stretched into a thin 



THE WASHING OF CRUDE RUBBER 



31 



and corrugated sheet as indicated at L. As the crank shaft continues 
to revolve, the rubber sheet becomes thinner as it descends between the 
jaws. During this operation water is forced against the rubber 
from nozzles M and N. At the lower ends of the frames B and C 
are corrugated jaws R, which are opened and closed by the movement 
of the frame C and crush the rubber after it has passed through the 
stretching jaws E and F. The action of the machine tears the rubber 
so as to free the foreig-n matter, which is then washed away by the 
water. 

Early Washers. 
Some of the earlier machines, while not in use to-day, may have 
a suggestive value. Austin G. Day, the inventor of Kerite, very early 
produced a washing machine. The novelty lay chiefly in the use of 
chemicals and a vacuum process. His system was substantially as 
follows : 




Fig. 18.— The Sault Washer. 

The crude rubber was first cut into small pieces and w^orked in 
water to remove the largest particles of foreign matter such as wood, 
bark, dirt, etc. Then the water was drained off and the rubber placed 
in an air-tight cylinder A, (Fig. 17), above which were two small tanks 
C and D open to the air. These were filled with a strong solution of 
caustic soda which was pumped from a larger storage tank B where the 
solution was mixed. Connected with the air-tight tank were four pipes, 
two F and G, leading to the soda vats, one E to an air pump and the 
fourth H to the storage tank. 

After the rubber was placed in the cylinder and tightly sealed a 
partial vacuum was created by the air pump, thus exhausting the air 
from the interstices of the rubber. Then the caustic soda solution was 
admitted into the cylinder, its flow being rendered easy on account of 
the vacuum. On coming in contact with the wood and bark the solu- 



32 RUBBER MACHIXERY 

tion served to increase their specific gravity while it has no effect on 
the rubber. When the liquid had remained a sufficient length of time, 
it was drawn off into the storage tank, after which the rubber was 
removed and thrown into tanks containing water. The whole mass 
was thoroughly stirred, the wood and bark sank to the bottom while 
the rubber was left floating on the surface. 

In the Sault process. Fig. 18, the rubber is first cut into small 
pieces and placed in the tank A. Then a stream of water is allowed to 
flow over the rubber at the same time that it is subjected to the action 
of the cylinder B which is provided with a set of teeth C. These teeth 
pass between stationary serrated bars as the cylinder B revolves, 
by which action the rubber is separated from impurities such as bark, 
etc. These sink to the bottom of the tank below the screen E. 

In addition to the foregoing there are sundry individual machines 
and processes of minor importance in use in various factories for the 
further cleansing and treatment of crude rubber. 

For example : In the production of a certain grade of rubber great 
difficulty was found in getting rid of the great amount of woody fibre 
that was present. After the rubber had been shredded both rubber and 
wood floated on the surface of the water, and if put through ordinary 
roll washers much flbre was imbedded in the rubber. One solution of 
the problem was a method of dissolving the wood fibre by treating the 
mass with a strong alkaline solution. After many experiments a simple 
process for removing most of it mechanically was invented. It was this : 
to float the shredded rubber and flbre into a tank that could be hermet- 
ically sealed. Air was then forced in and the pressure freed the minute 
globules of air that clustered about each shred of flbre, and the shred, 
water-logged, sank to the bottom out of the way. 

The above covers pretty fully rubber washing where water alone 
is used. Where rubber is washed free from resins, for example, and 
solvents are used, a radically different apparatus is necessary. That, 
however, is another story. 



CHAPTER II. 

CRUDE RUBBER DRYI^^G. 

IT is only recently that the drying of crude rubber has been done 
with any regard to economy and efficiency. For years rubber in 

thick sheets hung in open rooms and dried and '"aged" as best it 
might. If after many failures certain types were too weak to hang 
and proved to be so by dropping in sticky heaps on splintery floors, such 
rubber was reluctantly spread upon shelves. Then came the partial 
heating of the dry room by steam pipes; then ventilators to allow the 
moisture-filled a^r to get out, and then the fan, the fan blower and the 
vacuum dryer. 

There are four systems possible: air drying without artificial 
heat, the heated air current, the vacuum system, and what is 
called the dessication system, that is, utilizing hygroscopic materials 
such as calcium chloride. Of these there are but two that are con- 
sidered practical — the heated air current, and the vacuum system. 
In the first, the drying room is fitted with steam pipes, usually placed 
about the side walls. The heat is generally given off from steam cir- 
culating through such pipes. Excellent results, however, have been 
obtained from heavy oils that were first heated and then pumped slowly 
through the pipes. Drying rooms of this type necessarily take up 
much space, and to be efi^ective should be constructed so that once the 
air is saturated it should be automatically removed by fan or blower, 
and then fresh, comparatively dry air introduced. An ideal adjunct 
to this system would be a preliminary drying of the air, either by 
chilling it or passing it over some hygroscopic material, then heating it 
and passing it into the rubber drying room. Esch, in his valuable 
hand book, describes an air current apparatus known as the channel 
dryer,* which will be described later. 

The vacuum dryer, first brought to the attention of the rubber 
trade in Europe by Passburg, and successfully introduced into America 
by J. P. Devine, has become almost indispensable in modern plants. 
So necessary is it that a dozen or more machine builders are now sup- 
plying vacuum dryers of their own. Mr. Devine's own claims for 
• vacuum dried rubber are worth noting. f He says: 

* "Handbook for India Rubber Engineers," by Dr. T\"erner Esch, Hamburg, 
1912. 

t "Problems in Vacuum Drying," by J. P. Devine, India Rubber World, 
July, 1913. 



V' 



34 RUBBER MACHINERY 

''Until the introduction of tlie vacimni drying apparatus very 
primitive methods were employed, and occasionally an advocate is still 
found, who asserts that the hot air method is necessary for the proper 
curing of some particular grade of rubber. The fallacy of such asser- 
tions is proved by the use of the vacuum apparatus in drying every 
grade of crude rubber. 

"'While it is true, considerable thought was given to improving proc- 
esses for drying rubber, there were no striking departures from the 
antiquated method of using hot air as the heating medium. The dust 
and dirt that would settle upon the rubber were the least of the evils ; 
the construction of special drying rooms from which direct sunlight was 
excluded, and provisions to eliminate dust and dirt, and the regulation 
of temperatures for various grades of rubber, as well as the attempt to 
drv the air before beinp; admitted into the drvino; room, all contributed 
to avoid the deterioration of the rubber by such means; but the value 
of these improvements was doubtful as they only tended to reduce 
the effect of high temperatures with a consequent prolongation of the 
drying period. The fact is that the two insidious enemies of rubber 
are heat and oxygen and these elements are. and always will be present, 
and necessarilv so, in anv svstem of hot air drvino-. Thev are deter ior- 
ating agents and their elimination is most essential for the proper 
drying of rubber. Their elimination by the vacuum apparatus has 
^ proven the superiority of the vacuum-dried rubber in the processes of 
its manufacture. 

'^Another and serious objection to the hot air system of drying 
rubber is, that rubber as ;it -comes from the washing machine, contains 
a very large proportion of mechanically bound moisture. While this is 
readily given off in the hot air drying room, its expulsion causes a con- 
traction of the rubber, which, with the oxidation constantly taking 
place, causes a hardening of the surface that prevents the elimination 
of the last moisture within the rubber, except by a very prolonged dry- 
ing period, during which time the rubber is further subjected to oxida- 
tion and not unlikely to excessive heat. Unless the last traces of 
moisture are eliminated, ''blowing" is sure to result during the follow- 
ing stages of its manufacture. 

"We still hear occasionally about 'ageing' rubber; but in reality 
this is simply the removal of the final traces of moisture; as stated, 
under atmospheric conditions, this can only be accomplished by a pro- 
longed drying period, while under vacuum the rubber is thoroughly 
dried in a very short time, and in practice rubber is immediately 
worked up after removal from the vacuum dryer. 



CRUDE RUBBER DRYING 



35 



''The deter ioratins: 



agents — oxygen' 



and excessive heat — can be 



eliminated only by the vacuum process and apparatus. This process 
and apparatus alone afford the proper conditions to dry rubber rapidly, 
uniformly and thoroughly at a low temperature and without oxidation, 
independent of climatic conditions. 

"It must be borne in mind that under atmospheric conditions a 
rapid boiling can only take place at 100 degs. C. or 212 degs. F., and 
that as the temperature decreases, the drying time is extended ; while 
under the vacuum the boiling point is greatly decreased and increas- 
ingly^ so as the barometric reading is approached. To illustrate, under 




Fig. 19. — Vacuum Shelf Dryer, Condenser and Pump. 



a vacuum of 29 inches water boils at 25 degs. C. or 77 degs. F. Kubber 
dried in the vacuum chamber, while the first free water is being 
removed, will not need to be heated, practically, above the boiling point 
of water at that particular vacuum. As the moisture is evaporated 
from the rubber, naturally the temperature of the rubber being dried 
tends to increase ; to prevent any overheating the supply of the heating 
medium — steam or hot water — is regulated accordingly and entirely 
shut off before the final drying ; the last traces of moisture are therefore 
drawn off by the latent heat in the dryer accelerated by the high 



36 RUBBER MACHINERY 

vacuum. Because seemingly high temperatures are used at the begin- 
ning of the drying process to expedite e\'aporation, the erroneous 
impression is sometimes formed that the rubber is overheated in the 
vacuum chamber ; but in a properly constructed vacuum chamber with 
its auxiliaries — condenser and pump — properly balanced, the applica- 
tion of well-known physical laws absolutely prevents any overheating 
if only reasonable care is taken in its operation. 

''In an average establishment of today, making a general line of 
rubber goods, two tons of crude rubber is a conservative estimate of its 
consumption. If the old hot-air method is used, in order to properly 
and thoroughly dry the washed and sheeted rubber, six weeks are con- 
sumed in the drying process. Seventy-two tons of rubber would be 
hanging in the drying lofts, which at 75 cents per pound, would repre- 
sent an idle investment of $108,000 on raw material, the carrying 
charge of 5 per cent, amounting to upward of $15 per day; and should 
the carrying charges for instance, factory space, etc., be included, the 
above sum would be greatly increased. 

''The same quantity of rubber could be more thoroughly and per- 
manently dried by one or two vacuum chambers in a day of ten hours, 
so as to "work up" whatever grade may be required for each day's 
output, and the initial cost of such an installation would be less than 
the cost of the old-fashioned drying rooms for the same quantity. So 
that the vacuum chamber pays for itself in the savings on investment, 
carrying, insurance and other fixed charges on raw material, as well 
as gives a flexibility to the factory for its daily production that cannot 
be obtained by any hot-air method. 

"To illustrate the great saving in factory space, a ^'acuum drying 
chamber having a capacity of approximately two tons of dry sheeted 
rubber per 10 hours, occupies a space of 8% feet high, 15 feet wide bv 
9 feet long; and its auxiliaries, the condenser and the pump, can be 
conveniently located at any place in the factory in proximity to the 
dryer. 

"In cases, however, where complaints have arisen, the well-meaning 
people who were using such a dryer, being surprised at the capacity of 
the apparatus far exceeding their expectations, thought it right to go 
still further by greatly increasing the charge of rubber and ultimately 
loading the apparatus with a much larger quantity than their apparatus 
was intended for. Of course, it was soon found that the increased 
charge could not be dried in the stated time, nor with the stated tem- 
perature of heating steam. As it is only human not to decrease one's 
desires, the natural human remedv was resorted to, that is, an increased 



CRUDE RUBBER DRYING 37 

temperature of heating steam and also a prolonged drying time. If 
Tou consider that the heating surface at a certain temperature within 
the dryer is intended for a layer of rubber of a uniform and certain 
thickness, its capacity, or rather the beneficial results obtained there- 
from, will be destroyed, or at least impaired, by an increased quantity 
of rubber per charge and an increased temperature of heating steam, 
because the heating surface itself remains the same; and it is this 
factor which remains constant — that upsets the results sought to be 
obtained by the violation of well known, but not considered, natural laws. 

''Experience has taught us to balance the necessary heating sur- 
face, to transmit a certain temperature to a certain layer of material 
to be dried; and it is quite erroneous to argue — though a common 
mistake — ^that the same beneficial results may be obtained from a larger 
quantity of material, by simply increasing the thickness of the drying 
material and increasing temperature, in the belief that the above men- 
tioned factor would increase proportionately. This, however, is not 
the case, as I will more fully point out. 

''If one takes the conductivity of rubber alone into consideration, 
and the gradual but decreasing evaporation of the water contained 
therein, it can very easily be understood that by altering some of the 
factors the physical laws, on which our calculations are based, will be 
violated without any such intention, and the penalty will be an unsatis- 
factorily dried rubber; — the cause of which is naturally placed at the 
wrong door. The fault is not in the apparatus, but in the method of 
its operation. The same remarks refer to the auxiliaries of an apparatus 
for drying rubber. These auxiliaries consist of a condenser and vacuum 
pump which are both calculated to correspond with the capacity of the 
vacuum apparatus they are intended to serve. 

"To illustrate what I mean: A vacuum dryer of a certain drying 
capacity and calculated for a certain purpose is intended to evaporate 
a certain quantity of water in a given time, and of course, which is 
essential, at as high a vacuum as is possible under practical working 
conditions. All this is, to a great extent, based on practical experience 
with the very material our apparatus is used for. If, however, the 
condenser, instead of handling the quantity of vapor for which its cool- 
ing capacity is calculated, is burdened with ever so much larger a 
quantity, the result must be detrimental in two ways : it not only re-acts 
on the dryer and the product it is supposed to turn out regardless of 
the time, but also re-acts on the working of the pump. 

"As regards the vacuum dryer, it is essential to have its inner 
space continuously freed from the vapor arising from the drying mate- 



38 



RUBBER M AC H IX FRY 



rial in order that no inner pressure mav be created in such apparatus 
to lower the vacuum. This can only be done by having the arising 
vapors taken care of in their entirety during their passage through the 
condenser, the capacity of which cannot be changed at will. 

''If more vapors are created than the condenser is intended for, such 
vapors will partly remain in the dryer, and create inner pressure. The 
inner pressure thus created consequently reduces the vacuum in the 
dryer and as a consequence the boiling point of the water contained in 
the rubber is increased, and the rubber will be heated up to a tempera- 




FiG. 20. — \'acuum Shelf Dryer. 



ture never intended, with detrimental effects to its quality. The over- 
charging, as I said before, aifects the efficiency of the pump and pre- 
vents it from creating the desired high vacuum. The reason for this 
is that a dry vacuum pump — the only type we have in mind in this 
discussion — is intended, dimensioned and constructed for pumping air 
and not vapor, particularly as the latter expands so enormously under 
vacuum. If the pump were intended to exhaust rarified or expanded 
vapor in addition to rarified or expanded air, its dimensions would be 
so enormous as to make its use practically impossible. 

''If, therefore, the dry vacuum pump has to exhaust vapors which 
have passed uncondensed through the over-taxed condenser, a burden 
is placed on the pump for which it was never intended ; its work becomes 



CRUDE RUBBER DRYING 



39 



inefficient and most naturally impairs the vacuum and efficiency of the 
whole installation for drying purposes." 

On the other hand, authorities like Dr. Werner Esch and Adolph 
Heil claim that while air drying may bring about slight oxidation it 
never results in depolymerization from heating. Vacuum drying, 
however, often results in quite an appreciable depolymerization.* 

Where the rubber will not sheet and is in the form of scrap, a 
centrifugal dryer is sometimes employed, but the rotary type of vacuum 
dryer used in drying reclaimed rubber is to be perferred. Vacuum 
masticators are also used to an extent in crude rubber drying. 

Vacuum Dryers. 
Fig. 20 shows the Devine vacuum chamber equipped with con- 
denser and vacuum pump. The dryer consists of a cast iron chamber A 
which contains a number of steam-chambered shelves C placed one above 

/V^iGSn C. D 




Fig. 21. — Cylinder Vacuum Shelf Dryi 



the other. The rubber is placed on the shelves or it may be placed in 
the metal trays D. The shelves are strong enough to withstand a pres- 
sure of 100 pounds per square inch. The vacuum is created by the 
air pump E while steam passes through the inlet F, into the hollow- 
shelves and out through the pipe G. The temperature is regulated by 
valves in the steam pipes, the pressure being recorded by the steam 
gage H. A vacuum gage K is attached to the top of the dryer. Be- 
tween the vacuum pipes L and M is a condenser N, to condense the 
vapor from the rubber. The condenser cylinder is filled with brass 



* "Handbuch der Gummiwaarenfabrication, 
Esch, Hamburg-. 



by Adolph Heil and Dr. V^^erner 



40 



RUBBER MACHINERY 



tubes around which cold water is circulated, passing into the condenser 
at P and out at 0. It has an observation glass so placed that the amount 
of condensation may be noted. The receiver can be drained without 
retarding or interfering with the drying, by a by-pass R. The doors are 
provided with observation glasses 8 through which the condition of the 
rubber may be observed. 

In rig. 21 is shown a simple form of horizontal cylinder vacuum 
dryer. The cylinder A contains a series of hollow iron shelves B con- 
nected with multiple steam inlets C and outlets D. These are attached 
to a removable plate on the side of the cylinder so that the steam passes 
directly into each shelf. The rubber is placed in trays E on the shelves 
and the doors F and G are closed, after which the air is exhausted by a 
pump attached to a pipe leading from the connection H. 




Fig. 22. — Vacuum Dryer. — German. 



Kef erence to Tig. 22 will serve to give an idea of the enormous size 
of some vacuum dryers. This illustration shows a German type about 
15 feet high and 20 feet long. It does not, however, diifer in prin- 
ciple from the other vacuum dryers. The cylinder A is provided 
with a connection B at the top for attaching the vacuum pump. The 
steam enters at C and passes out at the lower side into the steam trap D. 



CRUDE RUBBER DRYING 



41 



The Channel Dkyee. 
In Fig. 23 is shown the Channel Dryer. This is a dry room fitted 
with an oyerhead mechanism that carries the sheeted rubber from one 
end to the other. Dry, hot air is forced through the room in the oppo- 
site direction to which the rubber travels. Thus the dryest rubber 
comes in contact with the dryest air. After the dryer is loaded, the 
doors are closed and the hot air forced through by fans. When the 




Fig. 23. — The Channel Dryer. 



sheets of rubber that hang at the end through which the hot air enters, 
are dry, the doors are opened and those sheets remoyed. The rest of the 
partially dried rubber is then moyed forward. This leaves room for a 
fresh supply of wet rubber at the other end. It will thus be seen that 
the traveling chains only move when loading and unloading. In the 
illustration, A shows the sheets of rubber hung over a wooden grill B. 
The grills, with their load of rubber, are attached to the crossbars C 
which, in turn, are fastened to the endless chains D. 

The Stuetevant Dryek. 

Fig. 24 shows the Sturtevant dryer for crude rubber which will not 
hang on cross rods. The drawing shows a partial cross section through 
the drying rooms with a blower D, attached to the lower compartment. 
The rubber is carried to the upper floor A either by a conveyor or in 
crates, and spread out and left until partly dry. It is then dropped 



42 



BUBBEB M AC my E BY 



tliroiigli the opening B, falling on the floor C , where the drying process 
is completed. This drver may have walls and roof of any ordinary ma- 
terial, btit the floors are made of expanded metal or perforated iron 



^ 



1 ^ 



^ 



¥=^ 



X 



\ C 



V 



V 



V 



V 



/eo 




Fig. 24. — The Sturtevaxt Dryer. 

plates, through which hot air is blown. In erecting a building for 
this work it is usually estimated that one cubic foot of air will absorb 
two grains of moisture, and that about 50 per cent, of the air shottld be 
re-circulated. 

The ••Deytextoe.'"'' 
The ''Dryventor/' shown in Fig. 25. is a type of dryer which has 
been used for vears for extractino- moisture from fruits, but which 




The "Dryvextor." 



has been adapted with slight alterations, for drying rubber. The pro- 
cess consists essentially in subjecting the rv.bber to moving currents 
of dehydrated air. having a temperature suflicient to efl'ect rapid extrac- 
tion of the contained water, but not to injure the rubber. 



CRUDE RUBBER DRYING 



43 



Referring to tlie illustration, there is a series of refrigerating 
coils A, over which air is drawn, through a screen, by a suction fan 
enclosed in the casing B. In passing over these coils the moisture in 
the air is condensed and precipitated. This dehydrated air is then 
heated by passing it over a series of steam coils, located in the end of 




Fig. 26. — Fan. 
Motor Driven. 



Fig. 27. — The Sturtevant Blower. 

the air chamber at C. It is then blown through the passage D and 
against a series of baffleplates in a casing E. These plates deflect it 
downward over the rubber, which is spread on the screens F. The air 
passes out of the chamber G through a passage at the bottom. The dry- 
ing room is divided into compartments, and the warm air may be sent 
through one or all of these by regulating the dampers controlled by the 
handles H. 



Vacuum Pumps. 

The efficiency of the vacuum drying apparatus depends largely 

upon the pump used to maintain the vacuum. Rapid evaporation at a 

low temperature necessitates the maintenance of a high vacuum. The 

pump shown in Fig. 28 is a good example of the horizontal type. It 



44 



RUBBER MACHINERY 



is of the double-acting, steam driven, rotary valve type in which the 
steam engine and vacuum pump are direct connected and built with 



an integral frame. 




Fig. 28.^ — Steam Driven Vacuum Pump. 



Fig. 29 shows another two-cylinder horizontal vacuum pump, of 
the two stage, motor driven type. This pump has an electric motor 
attached directly to the bed of the pump and drives the large gear on 




Fig. 29. — Motor Driven Vacuum Pump. 

the pump shaft through a pinion on the motor shaft. The air valves 
are self-seating without springs and have a by-pass for rarifying the 
air left in the clearance space at the end of the stroke. 



CONDENSEKS. 

The condenser is used to reduce vapors to liquids. Fig. 30 
shows one form of surface condenser in which the condenser A and 



CRUDE RUBBER DRYING 



45 



receiver B are combined in one. The vapor passes from the vacuum 
chamber into the condenser at C and through a series of metal tubes D 
which are surrounded by cold water which enters at E and passes out 
at F. On striking the cold tubes the vapor is condensed and flows into 
the receiver as water. By the by-pass G, the water is drained off. The 
pipe leading to the vacuum pump is attached to the condenser at H. 
This device is shown connected with a pump and vacuum dryer in Fig. 
20. 

Fig. 31 shows a cascade injection condenser. By means of a series 
of shallow adjustable trays A, the cooling water, which enters the con- 




FiG. 30. — Surface Condenser. 



Fig. 31. — Injection Condenser. 



denser at B and leaves at the lower end C, flows in thin sheets, falling 
from one tray to another. This exposes the vapor to a large cooling 
surface, resulting in quick condensation. The vacuum pump is attached 
to the pipe D and draws the moisture from the vacuum dryer through 
the connection at E. Most of the vapor is condensed by the cascades 
of water falling from the trays, but any which escapes passes up into F 
and is condensed in the cylinder G, and drained off at H. This type of 
condenser is used where large quantities of vapor are to be handled. 



46 RUBBER MACHINERY 

Peecextages of Moisture in Rubber. 
In this connection it is interesting to know, at least approximately, 
how much moisture the hot air current or the vacuum dryer extracts 
from crude rubber. The percentages in the table of shrinkages that 
follow include water and foreign materials ; it is the former, however, 
that is responsible for most of the loss in weight.^ 

Percextage Loss of Weight ix Dryixg. 

Pearson. Clouth. 

American. 

Para fine 15 to 20 18 to 20 

Para Xegroheads 40 

Para Matto Grosso 28 

Mangabeira 20 to 35 40 to 42 

Brazil sheets 33 

Caut^ho 20 to 40 37 to 42 

Mollendo 14 

Cameta 37 to 42 

Peruvian scraps 25 

Santos 28 

Central America 20 to 40 

Africax 

Tongues (no specific origin) 18 to 25 
Flakes ^' '' " 25 to 35 

Thimbles '' " " 15 to 35 

Accra 20 to 40 

Bissao 35 to 43 

Gambia 30 

Bio l^ounez 35 

Conakry . 36 

Calabar lumps 36 

Casamance 52 

Leone Niggers 35 

Bassam 30 to 36 

Cape Coast, Salt Pond, Addah, Quittah, Axim : — 

Buttons 20 to 30 40 

Biscuits 20 to 30 35 to 42 

Flakes 30 to 35 48 

Lumps 30 to 40 

* "Rubber, Gutta Percha and Balata," by Franz Clouth and B. F. Voigt, 
Leipzig-, 1899: and "Crude Rubber and Compounding Ingredients," by Henry 
C. Pearson, New York, 1909. 



CRUDE RUBBER DRYING 47 

African — ( Continued. ) 

Pearson. 

diggers 20 to 35 

Lagos buttons 25 to 35 

Lagos lumps 30 to 40 

Lagos strips 25 to 35 

Cameroon balls 18 to 25 

Cameroon clusters 18 to 28 

Congo buttons 25 to 30 

Congo balls 20 to 35 

Upper Congo 20 to 25 

Upper Congo, red balls .... 18 to 22 

L^pper Congo, Lopori 16 to 22 

Kassai black twists 18 to 22 

Kassai red twists 20 to 25 

Kassai ball twists 20 to 25 

Benguela and Loando sausage 16 to 20 

Benguela and Loando niggers 18 to 20 

Mozambique 10 to 35 

Madagascar 25 to 55 

Madagascar pinky 30 to 35 

Majunga black 30 to 40 

Majunga niggers 30 to 40 

Asiatic. 

Assam 8 to 45 31 

Assam Xo. 1 10 to 15 

Assam Xo. 2 20 to 30 

Assam Xo. 3 30 to 35 

Penang Xo. 1 10 to 15 30 

Java is^o. 1 10 to 15 13 to 23 

Borneo 30 to 45 20 to 55 

Rangoon 45 

Chinde 11 



Clouth. 






48 


37 


to 


45 


35 


to 


43 


35 


to 


43 
23 
23 


12 


to 


18 


18 


to 


30 


18 


to 


30 


18 


to 


30 


15 


to 


24 


18 


to 


25 


15 


to 


35 

40 


35 


to 


38 



CHAPTER III. 

DRY-SIFTIXG AXD BATCHIXG OF COMPOUXDIXG 
IXGREDIEXTS. 

THE scores of metallic oxides, sulphides and earthy ingredients 
that are used in rubber compounding must be dry, fine and clean. 
As they are often bought in bulk this necessitates special recep- 
tacles and machines for their storage and treatment before they are 
ready for the mixing mill. Every factory, therefore, has its compound 
room for weighing out batches. An adjunct is the storage room where 
the ingredients are prepared for weighing. For drying earthy materials 
bins are employed that may be heated and in which are stirrers. 
Materials that have a tendency to absorb moisture are kept in zinc- 
lined bins fitted with tight covers. Formerly all of the dry ingredients 
were weighed out in quantity, mixed together and run through burr 
stone mixers. Then a certain portion of this agglomeration was weighed 
out to go with so much rubl)er for a batch. 

Today, however, all of the ingredients are handled and weighed 
separately. After drying and sifting they are ready for the compoimd 
room. Indeed, in some plants they are delivered there by automatic 
machines from the sifters. Sometimes the room for preparing the 
ingredients is located directly above the compound room and small 
chutes are put in to carry the materials down. Such chutes must be 
fitted with stirrers, for if gravity alone is depended upon the materials 
choke and stick fast. 

The compounding room is built to accommodate the kind of work 
the factory produces. It is usually fitted with many large pigeon holes 
for massed rubber of various sorts, reclaimed rubber, etc. The sulphur, 
whiting and like ingredients are in bins and rarely in the original 
package. Oils are kept in small tanks from which the necessary quan- 
tities can be readily pumped. In some factories ordinary scales are 
used for the weighing. In others, scales that have arbitrary signs and 
unusually shaped weights, are used for the purpose of secrecy. For the 
same purpose the ingredients are often given false names and the com- 
pound cards are made up in cipher. 

Many of the best sifting appliances are also designed to mix dry 
powders. In the present practice in rubber manufacture, this is rarely 



DBY-SIFTIXG AND BATCHING. 



i-J 



done, the ingredients being kept separate during the drying and sifting, 
and assembled in the pans that go to the rubber mixer. 

Germax Recipeocati^^g Siftee. 
Fig. 32 shows an exceedingly simple and practical sifter that 
could be built in almost any machine shop. One or more sieves are 
placed in the sieve box A, and shaken back and forth by the con- 




FiG. 32. — German Reciprocating Sifter. 



necting rod attached to the crank B. 
the hinged cover of the sieve box. 



C is the dischar2:e and D beini^ 



The G-auxtt Siftee. 
Fig. 33 shows the Gauntt sifter and mixer, a type of machine 
which is often used for sifting compounding ingredients. The material 
is placed in the hopper A and is agitated by the spiral brushes B, 
which sift it through the screen C into the mixing cylinder D. Foreign 
materials, strings, lumps, etc., are discharged from the sifter through 
the spout E. The mixer has two opposed spiral agitators F with a 



60 



RUBBER MACHINERY 



number of blades G set at different angles to thoroughly agitate and 
blend the compounding materials by constantly reversing them and 
carrying them in different directions. The machine is driven from the 
belt pulley J? on a countershaft, through a pair of spur gears / and J . 
The gear / is keyed to the shaft K of the mixing cylinder, while the 
sifter brush is revolved by the sprocket chain L. These machines are 




Fig. 2)2). — The Gauntt Sifter. 

made in nearly a dozen different sizes, v/ith capacities from 10 to 100 
barrels per hour. A machine with a thirty barrel capacity occupies a 
space 8x2x5 feet. 

The Gaedts'er Sifter. 
In Fig. 34 is shown two interior views of an English type of 
combined sifting and mixing machine. The feed hopper A is provided 
with a gate M which can be opened or closed for controlling the ingredi- 
ents which pass from the hopper to the semi-cylindrical sieve C. The 
materials fall from the hopper into a helical brush B on the roller N. 
The brush forces the fine material through the sieve, while the lumps 
are carried along to the reducing portion of the brush P. This breaks 
up the lumps and passes them through the sieve C. Any foreign matter 
such as particles of stone or wood and irreducible lumps are automati- 



DRY-SIFTING AND BATCHING 



51 



callj thrown out through the spout II at the end of the sieve. The sifted 
materials fall into the mixing chamber F which contains an agitator 
mounted on the shaft G. After the materials are mixed the outlet I 
is opened and the contents discharged. Where there are no lumps in the 
materials and only a gentle sifting action is required, a different brush 
is used. The sieve can be quickly withdrawn as shown by the position 





Fig. 34. — The Gardner Sifter. 



of the dotted lines at D and another sieve of coarser or finer mesh 
inserted in its place. The brush is also removable. By loosening the 
thumb screws L the bottom portion of the mixing chamber may be 
opened as shown by the dotted lines J, for cleaning the blades. 



The Werner & Pfleideree Sifter. 
The apparatus shown in Fig. 35 is the Werner & Pileiderer spiral 
brush sifter, which is very convenient where small quantities of com- 
pounding ingredients are to be handled. The machine consists of a 
wooden box A in which revolves a spiral brush B fitting into a semi- 
cylindrical sieve which forms the bottom of the trough-like receptacle. 
The material to be sifted is placed in a hopper above the box and con- 
veyed along by the brush until all soft lumps are crushed. The fine 
material falls through the sieve while hard lumps and refuse are 
delivered through an outlet C. The pressure of the brush on the sieve 
may be adjusted by set screws at each end of the machine. Sieves of dif- 



RUBBER MACHINERY 




Fig. 35. — The Werner & Pfleiderer Sifter. 

ferent mesh may be used for sifting materials of different degrees of 
fineness. This machine is driven by pulleys D as shown, or by a hand 
crank when it is used infrequently. 




Fig. 36. — The Gyrator Sifter. 



DRY-SIFTING AND BATCHING 



53 



The Gykatok Sifter. 
The illustration shown in Fig. 36 is a different type of sifter from 
any of the foregoing. The sieve box is suspended from the ceiling by 
wooden hangers A and the removable sieves are held in place by clamps. 
The sieve box D is given a combined reciprocating and gyratory motion 
by the eccentric fly wheel B, which is driven by the belt pulley C. 
Thus the materials to be sifted are kept in constant motion. The swing 
of the box is counterbalanced by weights in the flywheel and a perfect 
running balance is secured. The material is placed in a hopper at E 
and after passing through the sieves it falls through the cloth chutes 
G into receivers placed under F. 

Automatic Measuring Machine. 
In Fig. 37 is shown a German apparatus for measuring quantities 
of powdered material and delivering the batches through a discharge 




Fig. 37. — Automatic Measuring Machine. 



chute. The material is stored in a hopper D. An agitator keeps 
it from clogging. A spiral conveyor E delivers it to the measuring 



54 



RUBBER MACHINERY 



cylinder A. In this is a conical piston with a sharp edge to further 
prevent clogging. This piston is drawn downwards by a roller L on 
the piston rod I by a pulling device M operated from the main shaft. 
The cylinder is oscillated by sectors rocked by a crank arm and link R, 
by engaging a cam rotated by gearing from the driving pulley Q. To 
discharge the batch the cylinder is turned until it is opposite the chute 
II. Then the rollers L worked by the discharge device N ejects the 
contents. The cylinder then automatically returns to the filling position. 

CoMPOUNDi^TG Scales. 
The old style beam scale is still used in many factories but it is 
not in the line of either accuracy or efficiency. The automatic scale, 
therefore, is fast displacing it. In weighing automatically the operator 




Fig. 38. — Small Automatic Scale. 

merely reads the weight ; the scale does the rest instantly. There are no 
loose weights, no calculating. Time and labor are saved, the cost of 
weighing cut and losses from wrong weights eliminated and disputes 
avoided. 

In both the old and the new types platform and beam scales with 
pans are used. The most convenient is a 25-pound automatic scale. 
See Fig. 38. This is equipped with a 2 to 10 pound chart, graduated 
in l/> ounces. Where big batches are weighed out the same type 



DRY-SIFTING AND BATCHING 

of scale is emplovecl but with a larger capacity. The portable plat- 
form scale, Fig. 39, really comes in three styles, one for the ship- 
ping room, one for special use such as tire weighing, and for batch- 




FiG. 39. — Portable Platform Scale. 



ing in the compound room. In the illustration shown, it is provided 
with a tare beam, that is of value in the receiving department, or in 
recording the weight of pans or trucks. 



56 RUBBER MACHIXERY 

The Ross Pulveeizixg Mill. 

It is sometimes necessarv to have a grinding apparatus for lumpy 

material. The mill, shown in Tig. 4:0. is a powerful machine of 

large capacity for grinding moderately hard substances such as flour of 

sulphur, dry colors, litharge, rosin, oxides of lead and zinc, whiting, etc. 




Fig. 40. — The Ross Pul\t:rizixg Mill. 

It operates on the attrition principle, having two steel cages revolving 
in opposite directions at high velocity. The materials are fed into the 
hopper at the top and discharged from an opening under the casing. 

EoTAEY Deyee. 

There are various t;s']^)es of dryers for compounding ingredients. 
As a rule they are designed especially for individual use. One that is 
used in Europe to an extent is the rotary dryer shown in Tig. 41. This 
operates without vacuum, yet has a large drying capacity. It consists 
of a hollow cylinder, through the middle of which, a little below center, 
rims a hollow shaft. To this shaft, on the interior of the cylinder, are 
attached stirring blades. Against the walls of the cylinder on the sides 
are arranged steam pipes. 

Referring to the illustration, C and D represent the ends of the 
hollow, steam-heated shaft. The blades on this shaft are represented 
by H. A is a hopper, through which the material to be dried is fed. 
F is the discharge port for dried material. E, E are hand holes. G is 
a stack for vapor exhaust. There may also be seen on the lower half 
of the cvlinder, entrance and exhaust ports for the interior steam pipes 
B. 



DRY-SIFTING AND BATCHING 



57 




Fig. 41. — The Rotary Dryee. 

Automatic AVeighitntg or Compouts^di^tg Ingeedients. 
The triple g^g\ automatic weighing machine shown in Fig. 42 is 
now being experimented with in large rubber factories. It is not yet 




Fig. 42. — Triple Gang Machine. 

wholly adapted for rubber work but its possibilities are many. It is a 
swift, accurate and secretive weighing mechanism which works faster 
than any expert human weigher. It is already used in a variety of 



58 RUBBER MACHINERY 

industries where dry ingredients are weighed and batched. The sug- 
gestion is that a gang of these machins could handle the ingredients 
that go to make up a compound, one machine to weigh whiting, another 
litharge, still another sulphur and so on. Each machine takes its 
material from a bin, weighs it and delivers it into a common pan. 



CHAPTER IV. 

THE MIXIXG OK COMPOLWDHsTG OF EUBBER. 

DEY mixing, that is, the incorporation of various compounding 
ingredients into rubber, is very generally done on machines 
called mixers or grinders. These machines are also used for 
massing or breaking down, refining and warming. 

The first rubber mixer of which we have any record was a machine 
made after the pattern of the "pug-mill" used in brick yards for the 
kneading of the clay. In this the rubber was treated with camphene to 
make it less refractory. 

The next step was the use of heavy wooden rolls set in a wooden 
frame, a solvent still being employed to soften the gum so that it could 
be worked. From this it was not a long step to the iron rolls, which 
were found to wear much better, and w^ere not affected by the camphene 
or benzine used in the sticky compound. 

At this stage of the industry, it was discovered that heat softened 
the crude gum, and yet did not make it sticky as did the solvents. A 
practical application of this knowledge was the hollow steam-heated 
roll that was almost immediately produced, and that made possible "dry 
mixing." 

The Chaffee Mixee. 

Edwin M. Chaffee, one of the pioneers in the American rubber 
industry and a co-worker with Charles Goodyear, was the inventor of 
the first iron roll, steam heated rubber mixer. It was a two-roll ma- 
chine. Fig. 43 showing Chaffee's own sketch of it. The drive roll A 
was six feet long, 27 inches in diameter, and chambered for steam. The 
second roll B, was of the same lengi:h and 18 inches in diameter. The 
larger roll was the fast one, the ratio being two to one. Above this roll 
were ^ve bars C, II/2 inches thick, 12 inches wide and six feet long. 
These were placed side by side, three-quarters of an inch apart. Their 
lower edges were convex and by the screws D adjusted to any desired 
distance from the roll A. Similar screws E were used to adjust the dis- 
tance betw^een the rolls A. and B. Beneath roll B was a movable feed- 
ing apron F passing over small rollers G and H. The operation of the 
machine was as follows : 

The rubber, cut into small pieces, was spread upon the apron and 
carried between the rolls where the steam heated rolls softened and 



60 



RUBBER MACHIXERY 



sheeted it. This sheet then passed under the bars C. The spaces be- 
tween the bars were filled with compounding ingredients in powder 
form and mixed with the rubber as it passed over the roll A. 

A few of the first steam-heated grinders are still in existence, and 
are worthy objects of curiosity. These machines were invariably run 
by belts, a huge wooden frame standing by the side of the machine in 
which hung a fast and loose pulley. The pulley shaft was provided 
with a large gear driven by a pinion set near the floor. This pinion 




t. < ■ ^ V ^ ^.jt. ^ <■ y «. % ^^\\^ ^^.^■ ^^\.^^<.^^\^ 



Fig. 43. — The Chaffee ]\Iixer. 



was on a shaft that ran across the back of the grinder, and at its 
extreme end held another pinion, which in turn, engaged with the large 
gear that turned the front roll. A similar shaft ran under the machine 
and, taking its power from the driving gear of the front roll by means 
of its pinion, turned the back roll. Thus the power was transmitted 
entirely around the grinder before it was applied to the rolls. This 
type, with modifications, continued to do its shiftless work for many 
years. It was a slow-running, noisy machine, mixing batches of twelve 
to fourteen pounds. Little by little necessity drove the manufacturers 
to make improvements. In this they were assisted by large machine. 



THE MIXIXG OR COMPOUXDIXG OF RUBBER 61 

builders who, learning what was needed — in many eases with difficulty 
— set themselves to build a practical, economical machine. The first 
thing they did was to throw aside the belted arrangement and put in a 
floor shaft. Then they hung a pinion on that shaft, and made it run one 
roll, while gears on the further necks of both rolls made one run the 
other. In the next place, the machine was made larger, the castings 
made heavier and the speed increased. Then came ''Jumbo" mills, 
three-roll machines, electric drives, etc., etc. 

The Mechanics of Mixing. 
The amount of work done by a common mixing-mill depends upon 
the surface-speed of the rolls in inches per minute, and the length of the 
line of contact between the two rolls. For example, an ordinary mixing- 
mill, with rolls 15'' x 40'', running 15 revolutions a minute for the fast 




roll and 8 for the slow roll will mix a certain amount. Doubling the 
speed will double the product for a day's work, — or, the speed remain- 
ing the same, doubling the length of the rolls would double the product. 
Strength of materials prevents making the rolls with a working face 
of much more than 80 inches long without increasing their diameter 
to an impracticable extent. An increase in the diameter of the rolls 
to gain this necessary strength for a longer span between bearings, 
creates another difficulty. The three diagrams herewith illustrate this. 
Fig. 44 represents a pair of 15-inch rolls and Fig. 45 a pair 
of 24-inch rolls, both drawn to scale. In each of these figures is 
a wedge of the shape the rubber would take in passing through the 
rolls. Its action is a simple wedge-action tending to split apart, exactly 
as an iron wedge would split a log. A slender wedge will split a log 
easily, while a blunt wedge would split it with difficulty. In the mix- 
ing-mill the same thina: occurs. The wed^^e is the rollino- bank of rubber, 

O O CO 

slender in one case. Fig. 45, blunt in the other. Fig. 44. This means tAVO 
thing's — not onlv that the roll shall be increased in diameter suf- 



(52 



BUBBEB M AC Ely E BY 



ficiently to have the same strength for the increased span between bear- 
ings, but also shall be increased still more in diameter to withstand the 
greatly increased resistance of the rubber when in the snape of a narrow 
and powerful wedge instead of a blunt and weak one. This very increase 
in diameter to allow for the additional pressure of the rubber makes the 
wedge still more narrow and powerful, and the diameter must still be 
increased in strength on that accoimt. This remedy rapidly aggravates 
the evil which it seeks to cure; so that, in doubling a working face 
between bearings, the diameter must be increased enormously, making 
a very radical change in the shape of the wedge and increasing all the 
general proportions of the machine in order to give the necessary 
strength to withstand the enormous pressure created by the action of 
this slender but powerful wedge. 




Fig. A\ 



If the object sought were to split the machine, as in the case of 
the log. a wedge designed in this shape would be an admirable means 
to this end. but as the opposite is desired, a change in this direction is 
the worst possible move, for the purpose is to crush the wedge in the 
cheapest manner possible, not to split the machine. The latter can be 
avoided by using large quantities of metal in massive proportions to 
give the necessary strength for the required resistance, and if this were 
the only drawback to doubling the capacity of the present machines, 
having the same labor cost in operating as now. the few himdred dollars 
additional first cost which they would require would be no serious 
obstacle in their construction, considering the labor saving each year; 
but there is one consideration which makes their operation economically 
impossible. The power required f )t running a small mill at the ordi- 



THE MIXIXCr OR COMPOUXDIXG OF RUBBER 63 

narv speed is about 15 horse-power. This is used up in two ways, — 
the internal work done upon the rubber, and the friction by the pres- 
sure of the rolls on the four bearings. The friction increases directly 
as the pressure, and, as we have seen, the pressure on these bearings 
when a slender Avedge is used increases enormously, and this increases 
the friction and the consequent power on the bearings all out of propor- 
tion to the work done upon the rubber. So that a mill having the same 
surface speed, but having twice as long a working face as the old mill, 
would consume not twice the power, but very much more than twice 
the power of the old mill. When power is generated in very large 
quantities and under the best conditions, such as pumping-stations, etc., 
an annual cost of $iO per horse-power is considered very good prac- 
tice, and is what is aimed at but only occasionally obtained. As gener- 
ated in the average rubber-mill, it costs nearly $55 per horse-power per 
annum. One may readily see that any saving made in labor may be 
more than lost in the additional coal bill. 

Theoretically, therefore, rolls should be made smaller, or run much 
faster to increase the output. The one difficulty in the past was that 
high speed created too much heat, and certain stocks were partly vul- 
canized before they were thoroughly mixed. Of course, the rolls cored 
for steam and piped for it were also piped for cold water. Various 
styles of coring were designed to cool rolls that were too hot. 

The Cowek'-Beagg Coolixg Role. 
In the Cowen-Bragg roll. Fig. 46, the water entering through the 
neck passes up close to the surface of the roll, back and forth, and out 
at the opposite end from which it entered. The illustrations show a 
longitudinal section of the roll and a cross section on the line x x. 




Fig. 46. — The Cowex-Bragg Cooling Roll. 

In operation, water enters the passage D in the direction of the 
arrow. On meeting the dam E it passes outwardly through the pass- 
ages I and the annular opening K into the channels F to the opposite end 
of the roll. Returning through annular passages G by another parallel 
channel F to the annular port -/, through radial passages to the central 



6i 



RUBBER 2IACHIXERY 



passage D at the opposite side of the dam E, from which point it is con- 
ducted away. It will be noticed that the water passes through the body 
of the roll, not only at its center but also very near the periphery where 
the cool water has opportunity to reduce the heat of the roll. 

Beagg's Coolixg Roll. 
Another Bragg roll embodies a series of circumferential water 
channels near the surface, these being connected with the inlet and 
outlet by radial passages running to the center of the roll. The water 




Bragg Cooling Roll. 



enters the roll at A (see Fig. 47) as indicated by the arrow and passes 
through the radial port C to the annular opening B. It then passes 
around the periphery of the roll and reaches the center through the 
radial port D, from which point it flows to the outlet E at the opposite 
end of the roU. This process is repeated, except that in the first inlet 
the water parses to the left toward the periphery, to the right in the 
second, to the left in the third, and so on. The return annular outlet 
pipes likewise lead alternatively to the right and left. In this way the 
flow of the water is in opposite directions from the coolest to the hottest 
parts of the roll. The water channels are iron pipes placed in the 
mould before casting. 

The Bragg BufLT-rp Roll. 
During his investigations, Bragg found that the internal stresses in 
casting and in operation were less if the roll were built up in composite 





G 






-B. A r. L 


>6 






i 


'7////////////^/////////////////////^^^ 










p 


~H 


^ 


/%%%^%^ 

'^///////A 




B' i 


K 


mm 


7^ 


K 


mm. 




G 




m 






'//iky///////////////////^^^ 


Vm 




Fig. 48.— The Bragg Built-Up Roll. 



THE MIXING OR COMPOUNDING OF RUBBEB, 



6i 



form. He, therefore, constructed a hollow roll surrounded by an 
outer sleeve. Referring to Fig. 48, the inner roll S is mounted 
on the flanges B B^ of the headers C C^, each provided with a journal 
D D^. Longitudinal grooves F are planed in the surface of the roll S. 
The outer casing E is then shrunk upon it. The course of the water 
for cooling is as follows : It enters at one end, fills the inner roll, and 
passes to the longitudinal grooves in its surface. It then flows through 
them, the length of the roll, and back through parallel grooves, then to 
the outlet in the neck of the inner roll at the opposite end from which 
it entered, where it is discharged. 

Referring again to the drawing, water is introduced at B and fills 
the interior of 8. It then passes through the radial passages N, to the 
annular groove K, then along the periphery of the inner roll through the 
first set of grooves F. It returns through the second set of longitudinal 
grooves into H and radial passages P and flows to the center at D^ on 
the opposite side of the dam Q where it is discharged. 



nail 



The Brewstee Cooling Rolls. 
One of Brewster's cooling rolls is shown in Fig. 49. It has inter- 
' projecting ribs A to provide strength and still to allow thin walls. 




Fig. 49. — The Brewster Cooling Roll. 



Two hollow headers B and C connected by perforated pipes D, form an 
interior cage. The header B is closed while C is connected to the inner 
end of the feed pipe G. This pipe has a ball joint F which allows it 
to turn with the roll while the pipe H remains stationary. Water 
enters the inlet pipe L and passes into header C and thence through 
the perforations E against the walls of the roll K. It fllls the roll and 
is discharged through an annular passage between the pipes H and N. 




Fig. 50. — Another Brewster Roll. 



6Q 



RUBBER MACHINERY 



Another type of roll invented by Brewster is shown in Fig. 50. 
This has two reinforcements AA, each having a hub center and fonr 
arms cast into the roll. Projecting inwardly from the walls of the roll 
are also radial ribs E E. These reinforcements strengthen the roll and 
leave clear passages C C from one end to the other. 

The Xoeeis Roll. 
The Xorris cooling roll. Fig. 51, has a thin ontei shell A and 
radial partitions C C extending from the central hnb G to the shell. 
These partitions do not extend the entire length of the roll bnt end at 
the shoulders D D\ beyond which are end chambers E E^. The inlet 
pipe F extends to the passage H which connects with the chamber E. 




Fig. 51. — The Norris Cooling Roll. 
The outlet K extends through the hollow hub G and connects with E\ 
The steam or water is admitted through the pipe F, passes through the 
chamber H, through E and into the openings between the radial parti- 
tions C C, back through the chamber E^ and out through the tube K. 

The Staxdard Mixer. 
Mixing machines or mixers for incorporating various fillers and 
ingredients uniformly into the crude rubber are made in many different 
sizes, and operated at various speeds to suit the ideas of the manufac- 
turers and the particular line of rubber product. Formerly a two-roi] 
mixing mill with rolls 15 inches in diameter, 36 or 10 inches long was 
considered large. Xow, some manufacturers have mixing mills with 
rolls 24 inchesin diameter and 81 inch face, or even larger. 

The standard machines are now made with rolls 16 x 10, 18 x 18 
to 54, 20 X 60 and 22 x 72 inches. The size best adapted depends on 
the compound to be mixed, but for general use a 20 or 22 x 60 inch mill 
is about as large as the operator can handle tc advantage 

These machines consist of two rolls made from either chilled or 
dry sand iron, set in a heavy frame. One roll has a driving gear on 
one end which is driven by a pinion on the shaft underneath ; on the 
other end of the drive roll is a gear which meshes into another gear 
on the end of the front roll. These gears are of different sizes 



THE MIX IX G OR COMPOUXDIXG 0' RCBBER 



67 



to give a friction or different speed to the front roll from that of the 
back roll, which assists in forcing the compound into the rubber. A 
standard friction has a ratio of about 1% to 1, that is, on a 20 inch 
mixing mill running the drive roll, sav 20 revolutions per minute, the 
front roll should run 13 to 14 revolutions per minute, giving a surface 
speed to the drive or back roll of 1256 inches, or 35 yards, and to the 
front roll of 838 inches, or 23 yards per minute. Some manufacturers 
prefer more, some less friction ; therefore, the friction used in factories 
varies from even speed up to 214 or even 3 to 1 ; but a good standard 





^,ijiip'(iiy» c^^p^B 


■ c 






""^T^^K^ui "^IH^flk^^i.^^^^^^^l 


BH^^^^^^hH^^p'^ jp 


3^ 


B-i- 


**f 1 tl^^BillF'in ^L ^ 


4^^m 


W 6 


1 


• ' ^^m^ 


^jMm 


B 


pk 


^^^plpilVl^^^ ^B 


_...- _.-*■""" «,„^3^ 


SBSi 





■*^ 


^ • 







Fig. 52. — Standard Single Ge.ared Mixes. 

on ordinary work is 1% to 1. Both rolls are either cored or bored, so 
that a constant flow of cold water can be maintained to keep them from 
getting too hot from friction. If rolls are not kept cool, the rubber 
will burn. 

Beneath each mixer is a wooden pan lined with zinc into which 
ingredients drop, that are not at first caught up by the rubber. The 
operator with a brush and shovel gathers this up and adds it from 
time to time to the mass that is being mixed. The pan, by the way, 
should be so set that it can easily be withdrawn at any time. The 
only tools that the mixer uses are the shovel, brush, and a knife. The 
latter is used for cutting the sheet from side to center and folding it 
in to insure even mixing, and in the final cutting ofi^ of the sheet when 
the batch is thorouo-hlv mixed. 



(38 RUBBER MACRIXERY 

The mill operator uses his own jiidgTaent as to the heat of the 
rolls necessary to mix various stocks. His test is to run his hand over 
the rolls and turn on steam or water as his experience may direct. His 
judgment also directs the cutting oft" of the batch and rolling it into a 
log or sheeting it into a thick slab when he believes the mass to be 
homogeneous. 

Mixers and indeed washers and calenders are fastened down by 
anchor bolts set in concrete foundations, or in more modern practice on 
a continuous bed plate of iron, cast in sections which allows of setting 
the machines at any distance from one another that may be convenient. 
A channel below the middle of the bed plate gives room for steam and 
water pipes, drip, etc. 

Fig. 52 affords a good example of the standard single geared mix- 
ing mill. G is the drive roll, D the slow roll, C the main driving gear, 
E and F the reducing gears. H, H are screws for adjusting the rolls. 
A is the clutch for starting and stopping the machine and B the lever 
for operating it. K and L are steam and water connections for heating 
and cooling the rolls. 

In a rubber footwear plant having three 20 x 60 inch mixing mills 
with dry sand rolls, the daily product for 10 hours on a month's run 
was -i.OOO pounds a day, consisting of compoim.ds for all kinds of 
uppers, solings. heels, friction, coating, etc. On some compounds such 
as heels the product was 6,000 pounds a day, but the average was as 
given above. The speed of these machines was: drive roll, 26 revolu- 
tions per minute: friction gears, IT and 27 teeth, front roll, 16^ 
revolutions per minute. 

In installing a number of mixing mills on a line of shafting, it 
is safe to figure on horse-power as follows: each 15 x 36 mill, 25 
horse-power; 16 x 10 mill. 30 horse-power: IS x 51: mill, 40 horse- 
power: 20 X 60 mill, 50 horse-power. 

For very heavy work the mixing mill is often double geared, 
that is. having a back shaft driven with gears from the main line, and 
a pinion and drive gear to operate each roll. 

In any mixing room there is bound to be a great amount of impalp- 
able and often palpable dust in the air. This settles everywhere, some- 
times on freshly calendered stocks which prevents adhesion in mak- 
ing up : sometimes on window ledges, beams and machinery and is 
later jarred off causing the same trouble. It is therefore well to 
have exhaust hoods over the mills so that all dust be removed before 
it can do harm. There is a further and more important reason for 
such hoods. Workmen are sometimes injured bv inhaling floating 



THE MIXIXG OB COMPOUNDING OF RUBBER 



69 



dust if not thus protected. Certain volatile chemicals also throw ofr 
fumes, which, if inhaled, result seriously. 

The Haubold Teakspakent Cover. 
It is sometimes desirable to cover the rolls of mixing mills to 
keep the dry dust from flying. For this reason Haubold introduced a 




X 




1- 


!) 


— ^ 




r 


2. 


I 


^(o) 1 




r'i -^ 


V 



Fig. 53. — The Haubold Mixer with Transparent Cover. 

mixer having a cover made of celluloid. This cover is shown at A in 
Fig. 53, enclosing the mixing space above the rolls B and (7. It is 
really part of a feeding device which both sifts and feeds the compound- 
ing ingTedients upon the rubber, while the mixing is in process. It is 
rarely necessary to add such a feed in ordinary mixing machines. When 
it is used, however, Haubold's celluloid cover prevents the light powders 
from flvino' and saves the mill tender much discomfort. 



Re fixers. 

The best grades of stock are usually refined after being com- 
pounded. A good standard refiner is equipped as follows: one 18 x 32 
inch chilled roll, one 12 x 32 inch chilled roll. The 18 inch roll runs 
about 26 revolutions a minute, the 12 inch roll 16 revolutions a minute. 

Refining is passing compounded stock between such rolls set 
closely together, thus breaking up small particles that may be present 



70 



RUBBER MACHINERY 




Fig 54.— Double Geared Rzftner. 




Fig. 55. — Refiner Equipped with Scraper. 



THE MI XIX G OB C02IP0UXDIXG OF RUBBER 



71 



and making the stock more homogeneous. The adjusting screws are 
made with finer threads than on mixing mills, and a scraper is placed 
over the fast roll to remove sticky stock. This scraper is a long knife 
often called a '^doctor," and is mounted on the frame of the machine 
in such a manner that it comes in contact with the roll. Sometimes it 
is hinged so that it can be thrown up out of the way when not needed. 
When in use it may be set hard against the roll by counter-weights, by 
a lever or by worms and worm gears. 

Fig. 55 shows a machine equipped with a scraper, shown at A. It 
is pivoted in bearings B and is raised or lowered by the worm gear C 
through hand wheels D. 

Rubber is often massed on one mill and mixed on another. The 
^' Jumbo" mill sho^^m in Fig. 56, both masses and mixes, the partition A. 
allowing it to serve as two machines in one. The partition is Y-shaped 




Fig. 56. — "Jumbo" Mill with Partition. 



and extends down between the rolls at B, and on the outside to the 
point C. This divides the mixing surface into two parts. The rubber 
is placed between the rolls on one side of the partition where it is thor- 
oughly massed. It is then removed and placed on the other side where 
the mixing is done, while a new batch is being broken down in the first 
side. 

Ceackees. 

Crackers are standard two-roll machines, made with corrugated 
chilled rolls and used for breaking down fibre stocks, etc. 

Standard sizes for crackers ^are 12 x 24, 15 x 24, 16 x 30, 18 x 36, 
etc. Best results are obtained from crackers bv using friction of 



72 



RUBBER MACFIIXERY 




Fig. 57. — Double Geared Cracker. 



2 or 214 to 1 on surface of rolls, the rolls being cut with about four 
corrugations to the inch and a spiral of about three inches per foot. 



The Peaece Mechanical Feed. 

The Pearce machine mixes compounding ingredients and feeds 
them into the mill. The operation of this machine, shown in Fig. 58, 
is as follows : 

The materials are weighed and placed in the box A in the com- 
pounding room. This box is then taken to the mixer and placed in the 
case B a bo re the cylinder C. It has a sliding bottom D^ operated by 
racks E, pinions F and hand wheel G. When the box is in position the 
bottom is opened, allowing the compounds to fall into the mixing cylin- 
der C. A clutch is then thrown in, which revolves stirring blades H. thor- 
oughly mixing the contents. Then a second clutch is thrown in, opening 
out the slides K, and the material falls evenly into the mill between the 
rolls L and M. This feeding may be done slowly or rapidly as the 
work requires. The mixing cylinder is driven through a chain N and 
sprockets Q and B attached to the drive roll L. The mixer can be 
attached to mills with rolls of anv dimensions. 



TEE MIXING OR COMPOUNDING OF RUBBER 



73 




Fig. 58. — The Pearce Mechanical Mixer and Feeder. 



The Beagg Automatic Mixek. 
The Bragg antomatic mixer, Fig. 59, is essentially a two-roll 
mixer combined with an endless feeding apron. This apron runs 
under the rolls and up and partly over the front roll, so that the material 
that would ordinarily drop into the pan is automatically returned 
between the rolls. The dotted lines in the drawing indicate the position 
of the apron before the mixing begins. This apron passes over a fixed 
roller D, a spring tension roller E and a movable roller F. The latter 
is attached to a pair of swinging levers G and handles H by which the 
apron is raised into contact with the roll B. A cross bar between the 
handles H carries brushes K which clean the apron. To prevent lateral 
play, the apron has a rib on the inner side which runs in a groove in 
the roll B. There are also end collars on the rollers which assist in 
keeping the apron in line. 



74 



RUBBER MACHINERY 



In operation, the apron keeps a sleeve of rubber against the roll 
and carries the slack toward the top where it laps and forms a fold. 




Fig. 59. — The Bragg Automatic Mixer. 

Cowen also designed a machine which is so nearly like that pat- 
ented by Bragg, that only a brief description is necessary. It is a two- 
roll mixer, with an adjustable apron for conducting the material from 
beneath the rolls, around one of them and to a hopper at the top. 

The Olier Mixee. 
Fig. 60 shows a French two-roll mixer which, with one or two 
differences, is one of the standard two-roll type. The additions are. 




Fig. 60.— The Olier 2\Iixer. 



THE MIXING OR COMPOUNDING OF RUBBER Y5 



an endless feed apron similar to that used in Bragg' s automatic mixer, 
and two adjustable plowshare blades. These are set so that the partly 
mixed sheet is turned in toward the middle of the rolls. In other 
words, it does continually what the mill tender does intermittently, 
turns the sheet away from the ends of the rolls and into the middle. 
The two drawings show an end view and a side elevation, both 
partly in section. The machine has two rolls A and B. Above them is 
a hopper G for compounding ingredients. At the bottom of the hopper 
is a cylindrical distributor D, driven by a chain E. This, distributes 
the ingredients over the rubber. To catch and carry back the unmixed 
ingredients to the roll A, an endless apron G is carried upon the rollers 
H, I and /. The roller H is mounted upon two side arms K, so that 
the apron may be raised or lowered. At the ends of the roll A. are two 
blades L, shaped like plowshares. They are raised or lowered by hand- 
screws M. When in contact with the roll A they scrape the rubber 
from the roll and turn it over. 

The Watkii^son Three-Roll Mixek. 
In Fig. 61 is the Watkinson mixer with the rolls placed as shown 
in the drawing on the right. The driving shaft A bears a pinion B 




The Watkinson Three-Roll Mixer. 



which drives the large gear G, keyed to the shaft of the main roll D. The 
gear E meshes with a gear G on the roll H while the gear F meshes 
with a similar gear on the roll K. The batch is shown between the 
rolls D, K and H. As the rolls revolve in the direction of the arrows 
the material below the rolls D and K is passed between the rolls D and 
H and carried back by the main roll to the starting point. 



76 



RUBBER MACHINERY 



The Wicks Three-Roll Mixee. / 

The Wicks mill, Fig. 62 has three rolls, A, B and 0, supported in 
end frames D. The roll B is adjustable horizontally by screws E, to 
the two rolls A and G. The front roll runs at friction speed of 1% io 
1 to the back rolls. In operation, the rubber is placed between the 




Fig. 62. — The Wicks Three-Roll Mixer. 

rolls A and B and forms a sleeve around B. The compounding 
ingredients are added and the two back rolls which revolve at a higher 
speed, force the ingredients into the rubber on the slower front roller. 



The Obermaier Mixer. 

In the Obermaier mixing mill, Fig. 63, the rolls are corrugated, 
the corrugations meshing with each other so that the faces are in contact. 
The roll A is the fast roll ; B is the slow roll. Arranged longitudinally 
of the roll i? is a scraper-knife C on a cross bar D. This knife has a 
corrugated edge which conforms to the shape of the roll. On the oppo- 
site side of the machine is a similar knife E mounted on pivoted arms 



THE MIXIXG OR COMPOUNDING OF RUBBER 77 




Fig. 63. — The Obermaier Mixer. 



F, allowing the knife to be swung in or out of engagement with the 
roll A. 

Masticatoes. 

After a number of years of experimenting, with little success, in 
endeavoring to devise a method of uniting pieces of crude rubber, 
Thomas Hancock, the pioneer in the rubber industry in England, 
finally constructed the machine shown in Fig. 64. It was his intention 
to tear the rubber into small pieces with this machine so that they 
might more easily be united by immersing them under pressure in hot 
water. The machine however massed them and led up to the masti- 
cator of the present day. 

The machine consisted of wooden frames A A bolted together, a 
hollow cylinder B, sl roll C in the center of the cylinder, and a crank D. 
Above the cylinder was an opening F through which the rubber was 
introduced. Both roll and cylinder were provided with sharp metal 
teeth. This first machine had a capacity of only two ounces of rubber 
but was soon succeeded by others of greater capacity, one of which, 
known as the ^Olammoth," is shown in Fig. 65. 

Masticators today are used in washing rubber, in breaking down 
and in mixing. The masticator mixer is very similar to the masticator 
washer shown in Chapter I. It of course is not a wet machine, and 



78 



RUBBER MACHINERY 




Fig. 64.— The Hancock Ortgtn/vL Masticator. 

is not fitted with mud traps, etc. The walls are also chamhered for 
steam and in some cases fitted for vacuum. 




Fig. 65.— The Hancock "Mammoth" Masticator. 



TEE 2IIXIXG OR COMFOUXDIXG OF RUBBER 



Y9 



The Uxiveksal Masticator. 

In the illustration of the Universal Masticator, Eig. QQ, J. is a 

chamber, in which revolve two blades B and C. The front side or cover 

D is supplied with counterweights E, to aid in opening. F is the hopper 

in which the compounding ingredients are placed and from which they 




, tv 




4iii 



Fig. 66. — The Universal Masticator. 

are fed automatically and continuously, at any desired speed, by the cone 
pulley G. Power is transmitted from the main driving shaft H to the 
blades B and C, by gears and pinions covered by guards I. The trough 
A and the door D are jacketed, and the blades B and C are hollow for 
heating or cooling. The rubber is placed in the chamber A, and when 
thoroughly masticated, the compounding ingredients are fed to it from 
the hopper F. When the batch is finished the door D is opened, and 
the machine automaticallv unloads into the car /. 



The Bridge Masticator. 
Another masticating machine is that built by Bridge, two exterior 
views of which are shown in Figs. 67 and 68. In this only one mixing 



80 



RUBBER MACHINERY 




Fig. 67. — The Bridge Masticator. 




Fig. 68. — End View of the Bridge Masticator. 



THE MIXING OR COMPOUNDING OF RUBBER 



81 



roll is employed which kneads the mass against the serrated sides of the 
cylinder that encloses it. This toothed roll is driven by the large gear B 




Fig. 69. — The Pointon Masticator. 



from the pinion C on the main driving shaft D , and thrown in or out 
of operation by the hand lever E. Counterweights N are used in open- 
ing the doors E and G. When closed these doors are held tightly shut 
by levers H which slide into slots /. The cylinder and the roll are 
chambered for steam, and the doors fitted with air outlets. 



In Fig. 



The PoiNTOiN' Masticator. 
69 is shown the Pointon masticator in end section, and 
a top view of the rolls or blades. The body or trough A is provided 
with a steam jacket B. The trough forms two semi-cylindrical cham- 
bers E and E, in which the blades rotate. At the lower portion the 
saddle H is formed. The masticator blades are both V-shaped and 
spiral. Rubber is carried around the two cylindrical chambers from one 




Fig. 70. — The Troester Masticator. 



82 RUBBER MACHIXERY 

to the other by the blades F and G. The V-shaped blade of one roll 
working with the spiral blade of the other, forces the rubber toward one 
end of the trough while the other blades force it toward the opposite end. 
The result is thorough mastication. 

The Teoester ]\Iasticator. 

The Troester machine, Fig. 70, employs one corrugated roll A by 
which the rubber is kneaded against the sides of the trough. The six 
doors B are placed side by side, extending the full length of the trough. 
These are arranged to be opened independently by chains C passing 
over quadrants D and over pulleys supporting counterweights. 

The Coolia^g Table. 

Many stocks, if left in rolls as they come from the mixer, hold 
enough heat to semi-v^ulcanize the inside. Such stocks should be 




Fig. 71. — Mill Room Cooling Table, 

taken from the mill in slabs instead of rolls and laid upon cooling 
tables. These tables have steel frames and tops of stiif wire 
cloth. They are made with two or three decks and have a capacity of 
one to two tons of mixed stock. Tig. Yl shows a two-deck table, which 
has a capacity of about one ton. 

Coi^TiNuous Bed Plates. 

Fig. 72 shows a mixing mill mounted on a continuous bed plate. 
It consists of two heavy castings B each having two T-shaped slots 



THE MIXING OR COMPOUNDING OF RUBBER 



83 



E and F running their entire lengtli. In the slots E the bolts G 
are placed to support the bearings of the driving shaft H. The bolts 




Fig. 72. — Mill on Continuous Bed Plate. 



I in the base of the machine frames are placed in the larger slots F. 
In this way machines of any length may be quickly mounted 
when the bed plates are once secured. The plates are usually attached 
by means of anchor bolts / set in concrete. Where a number of machines 
are set in line, several lengi:hs are bolted together, so that the slots E 
and F are continuous. 

The subject of safety devices in connection with mixers is of first 
importance. This will be found fully covered in the chapter devoted 
to Calenders. Motor drives applicable either to mixers or calenders 
are also there described. 



CHAPTER V. 

PKEPAKI^^G PABKICS FOE CALEXDERmG AIS^D 
SPREADI^^G. 

THE preparation of fabrics for a coat of rubber or for frictioning 
is a very necessary preliminary. The chief trouble maker, if 
such preparation is dispensed with, is moisture. To appreciate 
how much moisture is contained in an apparently dry bolt of duck, 
one needs only to put it in a vacuum dryer and note the amount of 
water extracted. There are also imperfections such as knots, nap, 
wrinkles, etc., which must be removed before the fabric is perfect. For 
this purpose, special machines are employed. 

The Fareel Six-Roll Dryer. 
In Fig. 73 is shown the Farrell six-roll drying machine. Each of 
the six rolls is 12 inches in diameter and any length up to 60 inches. 




Fig. IZ. — The Farrel Stx-Roll Dryer. 



They are made hollow and are fitted with steam connections. For 
high pressure, say 40 to 80 pounds per square inch, the rolls are made 
of cast iron and turned smooth. For low pressure of about 12 or 15 
pounds per square inch, the rolls are made of copper. The machine is 



PREPARING FABRICS FOR CALENDERING 



85 




Fig. 74. — The Multiple Cell Dryer. 

geared to run in either direction, that the fabric may be run through 
as many times as necessary. At each end of the frame there is a com- 
bination Yv^ind-up and brake so that the fabric may be wound up either 
at the front or back. The driving pulleys are 36 inches in diameter 
with a 6% inch face and are run at 50 revolutions per minute. The 
machine is 7% feet high and where the rolls are 5 feet long a floor 
space of T X 10 feet is necessary. 



The Multiple-Cell Deyee. 
The machine shown in Fig. 74 consists of twelve hollow cast-iron 
boxes. It is really a stack of boxes without side frames and is a good 
example of unit construction. That is, almost any number of individual 
cells can be assembled in a stack to suit requirements. Each cell con- 
tains three baffle plates to increase the radiation and is set on an angle 
so that the condensation is taken care of by gravity. Each cell is 
provided wdth three lugs, two on one side for steam inlet and outlet, 
and one on the other as a support. The lugs of the different cells 
are dow^eled and keyed and coincide, so that when steam is admitted 
to the top cell it passes through all of them to the bottom. A brass 
sprocket roller is journaled on one end of each cell. The sprocket 
rollers in the stack are driven by an endless chain, w^hich comes in 
contact with all of them. The fabric passes over these rollers and the 
heated cells, first over the top pair, then against their under surfaces, 



86 



RUBBER MACHIXERY 



then over the surface of the second pair and so on. At each end of 
the machine is a wind-up and brake so that the fabric may be run 
back and forth as many times as necessary. 

Fabric Steetching Machine. 
Taking the stretch out of fabrics, particularly those used in belt- 
ing and tires, is very necessary. Fig. 75 shows a front view of a 
machine for this purpose. 




Fig. 75. — Fabric Stretchixg Machine. 

It is simply a frame, carrying a series of tension bars, take off 
and wind-up rollers. The cloth starts at one end, is threaded over 
and under the bars and wound up on a floating roller at the front. 
This roller is supported on the ends of two levers pivoted in the center, 
with counterweights on the opposite ends. This presses the fabric 
against a square shaft. The friction revolves the take-up roller and 
winds up the fabric. 

Cloth Measukiistg Device. 

Fig. 76 shows a device which is often attached to calenders and 
fabric coating- machines for measuring fabrics. It may be attached to 



i 



I 



PREPARING FABRICS FOR CALENDERING 87 




Fig. 76. — Cloth Measuring Device. 

the frame of the niachine or to the frame of a separate wind-up roll. 
The cloth E passes from the machine over the measuring roller A and 
under a tension roller B. On the shaft of the measuring roller is a 
worm gear C which engages the teeth in the circumference of the dial 
D, the pointer being stationary. In most cases the measuring roll is 
one yard in circumference and the dial is graduated accordingly. 




^:3^ 



Fig. 77. — Cloth Measuring Counter. 



Fig. 77 shows a counter for registering up to 100,000 yards at a 
time. This is used with measuring rolls one yard in circumference, a 
small rod connecting a crank pin on the end of the measuring roll shaft 
with the lever of the counter. This device is so arranged that it may 
be set back to zero at any time. 



88 RUBBER MACHINERY 

SixGEixG Machines. 
In the manufacture of certain kinds of rubber-coated cloth it is 
essential to get rid of the fuzz left after spinning and weaving. Except 
in certain kinds of woolen fabrics this is done by singeing machines. 
In cotton cloth the singeing is sometimes done bv passing the yarn 
before spinning through a flame, but more commonly the work is done 
after weaving. 




Fig. 78. — The Granger Plate Singeing ^Machine. 



There are two types of singeing machines, or singeing houses, 
as they sometimes are called. In one the heat is applied by an 
iron plate under which oil is burned, the other uses a gas flame. In 
either case the essential features are : Steady heat applied evenly over 
the whole surface, an even speed so adjusted that the fuzz will be 
burned off without injuring or scorching the fabric, a draft so arranged 
that it will remove the burnt particles without causing any irregularity 
of the flame. 

Fig. 78 shows the Granger plate singer. It may have any number 
of plates from one to five, but in any case the lower deck contains one 



PREPARING FABRICS FOR CALENDERING 89 

more plate than the upper. The iron frame plates at the side are held by 
iron plates at the bottom, which rest upon brick or tiling. The singe- 
ing is done by bent plates of copper heated by an oil flame. A complete 
singeing plant includes, a singeing house, engine, air compressor, air 
storage tank, oil tanks and an exhaust blower. 




Fig. 79. — The Curtis & Marble Singeing Machine. 



The Curtis & Marble machine, shown in Fig. 79, is used for goods 
requiring especially complete treatment. The burners have a continu- 
ous slot, which is adjustable to different widths of cloth. Brass slides 
also shorten the flame as may be necessary. The rollers for the pass- 
age of the fabric are so arranged that the flame comes against the cloth 
twice. The passage of the cloth may be arranged to singe either side 
alone or both sides at one process. The gas is mingled with air in 
such proportion as to give the maximum heat and complete combustion. 
The means by which this is done is a fan blower and air reservoir con- 
necting with the gas pipes. The burners check the levers so that the 
machine cannot be stopped without turning off the flame. The brass 
rolls over which the cloth passes are kept cool by passing water through 
them. Various attachments are made for regulating speed, for cleans- 
ing the goods as they come from the singeing house and for delivering 
the finished cloth either in rolls or in folds. 



90 



EUBBEE MAC HI XE EI 



The Heath \^eetical Beushee. 
Fig. 80 shows the Heath vertical brushing machine for removing 
lint and dirt from cotton and other fabrics. It is made with three 
brushes for each side of the fabric, although other cleaning appliances 
such as emery rolls, sand rolls, card rolls or steel bladed beaters may be 
used in place of part of the brushes. The fabric passes vertically 
upward from the bottom to the top of the machine, guide bars being 




Fig. 80. — The Heath Vertical Brusher. 

employed to hold it in contact with the brushes and to prevent vibration. 
On the interior are dust chutes, through which the dust and lint pass 
to the bottom of the machine. At the bottom is a hopper with a pipe 
connected to an exhaust fan to carry away the dust. The brushes have 
stiff bristles, for cleaning cotton goods, while for more delicate fabrics, 
such as silksj soft bristles are used. The brushes run in adjustable 
boxes and may be set to bear heavily or lightly against the fabric. 
Hino^ed doors at the front and rear give access to the interior. The 
machine is made with tension and spreader bars and with draft roll 
for drawing the cloth through. The illustration shows the machine 
running in connection with a calender roller at the rear for smoothing 
out the fabric and putting it up in firm, hard rolls. 



PREPARING FABRICS FOR CALENDERING 



91 



Cloth Inspector. 
Cloth inspection for knots and faults is necessary before coating 
certain classes of fabric. The inspecting machine, shown in Fig. 81, 
is for this purpose. It has a cloth cradle with wooden rolls to hold a 
roll of fabric up to 18 inches in diameter. Where the cloth comes in 
larger rolls it is placed on stands. The cloth passes up the inclined 




Fig. 81. — Cloth Inspector. 

table in full view of the operator and any defects are easily observed. 
A rolling head at the rear, which winds up the fabric, has spreader bars 
to remove wrinkles and turned edges. The fabric is stopped and started 
by the pressure of a foot lever. There is also a reverse motion by 
which the goods are run backwards. These machines are built in widths 
from 30 to 108 inches wide. 



Railway Sewing Machine. 
For sewing ends of piece goods together a railway sewing machine 
is a great convenience. See Fig. 82. Before being sewed the cloth is 
drawn out to its full width and held smooth and straight by steel pins on 



92 



RUBBER MACHINERY 



the niacliine. The sewing head then travels across the machine, the 
fabric remaining stationary, and the ends are sewed together with a 
continuous chain-stitch. The sewing may be done close to the ends, 
causing very little waste in headings, and the stitches are easily drawn 
out when desired. The machine is adjustable for different widths of 




Fig. 82. — Railway Sewixg Machine. 



fabric and the machine head stops automatically at the end of each seam. 
As soon as one seam is finished a small hand wheel is turned and the 
sewing head is drawn back to the starting point ready for the next 
seam. The operator controls the starting and stopping of the machine 
by a treadle board at the front. A measuring attachment can be added 
to the machine for registering the leng-th of goods as it is rolled up. 



CHAPTER VI. 

CALENDEES. 

AVERY necessary preliminary to the making up of India rubber 
goods is getting the rubber into sheet form. Where the compound 
comes from the mixers in the form of a dry dough this is done by 
machines known as calenders. The calender consists of two heavy 
frames in which run two or more steam-heated rolls. These rolls lie 
horizontally one above the other and the warmed rubber forced between 
their smooth surfaces is spread into sheets. 



^pj4^^-v^^;^^__ 




^ V////A V////A 

Fig. 83. — The Chaffee Calender. 

Calendering is not an exact science. A boss calender man who is 
familiar with a certain line of stocks can get the heat of the rolls just 
right, can see to it that the compounded stock comes from the warmer 
at the proper temperature and can sheet the stock smoothly, of the 



94 



RUBBER MACHINERY 




Fig. 84. — Two-Roll Calender. 



proper thickness and without blisters. He is obliged to learn new 
stocks, however^ by experiment. This means that yards of stock are 
scrapped and warmed again, a loss of time and a detriment to the stock. 
Moreover, if stock badly run is passed through to the wind-up, it will 
be rejected by the cutters and come back to the mill room as scrap. 
This is often so softened that it cannot be used for the purpose first 
intended, hence another loss. 

The calenders shown in this chapter are such as are used in a 
variety of lines of rubber manufacture. Special types used only in 
individual lines, such as tires, footwear, etc., will be found in the 
chapters devoted to such industries. 

The first calender, shown in Fig. 83, was invented by Edwin M. 
Chaffee and diifers very little in principle from the machines 
manufactured today. It had four steam-heated rolls, A, B, C and 
D. Rolls A and D were 18 inches in diameter while the other two 
were each 12 inches in diameter. Roll B was geared to move much 
slower than the others, providing friction between A and B, and also 



CALENDERS 



95 



B and C. Where it was desired to use only the three lower rolls the 
upper one was disengaged and the cloth passed into the machine between 
B and C. This cloth on a roller E was passed around a number of bars 
F to provide tension. The rubber was fed between A and B, passing 
around B and coming into contact with the cloth between B and C 
where it was pressed into the fabric. The double sheet then passed 
around C and D and was wound up on a roller G. For colored goods 
the rubber was sometimes run into sheets and the coloring material 
applied, after which it was rolled into a compact mass and passed 
between the rolls repeatedly until thoroughly mixed. In other words^ 
the calender was used as a mixer. This machine was known as the 
^^Monster," so large did it appear to the mechanics of that day. 

Two-EoLL Calender. 
The simplest form of calender is the two-roll. It is not generally 
used in the United States but in Europe is quite common. It is used 
sometimes as a doubler and sometimes for sheetina;, for '^slabbino;'' and 





^^^^^K jr ^r^^^^^^^^^^^mmm ;;i3 ^^^^^^^^^^^^H 









Fig. 85. — Two-Roll Calender. 



96 



RUBBER MACHINERY 




Fig. 



-Three-Roll Calender — European Type. 



for belting. This machine is similar in construction to the three-roll 
calender described in detail later. 

As shown in Fig. 84, it has the frames A and B, with housings 
C and D at the top. The frames are connected at the top and bottom 
by strong braces, and rest on a foundation plate E. The upper roll F 
is adjusted vertically by the hand wheel P, while the lower roll G is 
mounted in stationary bearings. The rolls are hollow and provided 
with steam and water connections / and K. The machine is driven 
by the spur gear Q, the rolls being geared together by double helical 
gears R and 8. The adjustable guides L govern the width of the sheet. 



Thkee-Roll Calej^dee. 
The three-roll calender is the most generally used of all. 



sometimes geared for even motion 



It is 
sometimes for friction but usually 
for both. The foundation, frames and drive are practically the same 
as in the two-roll calender. The middle roll is the drive roll. The 
top and bottom rolls are adjustable by screws bearing against the 



CALENDERS 



97 



journal boxes. These screws are operated by worm gears and a hand 
wheel. There are sliding clutches on the worm shafts which allow 
for aligning the rolls. The rolls are chambered for water or steam 
and have stuffing boxes with goose necks that connect with steam and 
water pipes and an exhaust pipe to carry off the condensation. 

The drive roll has a friction pinion on the opposite end from the 
drive gear and the top and bottom rolls are driven from this pinion 





1 


^m^ 




P*^^^ 










*^liS 


"Slj^^^ 


1 








\ 






■3 - "iZZ 


1 


1 




|^?| 




m 










-m 








m ^m 


W 


1 






^9 










^^^jf^l 


^tH|k ^ 






1 


^^ 


^^^=«;~ -_^^.^ 


•-m 






«*"•-■ 


r 



Fig. 87. — Three-Roll Calender. 



with suitable gears to give a surface friction of 1% to 1. There are 
two speeds to drive the gear, one to secure a speed on the bottom roll 
of about 15 yards a minute, the other a speed of 25 yards a minute. 

In front of the calender is a friction let-off attached to the frame 
of the machine. This is constructed to hold a roll of cloth with more 
or less tension. On the opposite side of the calender is the wind-up, 
driven by spur gears or sprocket chain. By means of the friction 
discs as the roll of cloth increases on the wind-up arbor, the tension slips 
enough to make up for it. There is also in front of the calender a 
corrugated spiral spreader roll to take wrinkles out of the cloth and a 
heated roll to warm the cloth. 



98 



RUBBER MACHINERY 



The operation of the machine is as follows : The clutch is thrown 
into the low speed, which starts the machine. Steam is turned into the 
rolls to warm them up. A batch of warmed compounded stock is 
placed between the top roll and middle roll forming a sheet of the 
required thickness entirely around it. A roll of cloth is then placed 




Fig. 88. — -Three-Roll Triangle Calender. 



in the friction let-off, the end passed over the spreader roller over the 
heating roll and through the calender between the middle roll and 
bottom rolls and attached to the wind-up roller. The machine can 
be thrown into high speed. It requires about 30 horse-power to run 
this machine. 

The machines illustrated in Figs. 86 and 87 show views of three- 
roll calenders. The heavy cast iron frames A and B carry housings 
C and D at the top, and rest on a cast iron foundation plate E. The 
frames and housings are connected by strong cross braces. The three 
hollow, chilled steel rolls F, G and H are piped for steam and water. 
The steam and water inlet is shown at I, with the outlet at K. 
The rolls are mounted in bearings of phosphor-bronze with ring lubri- 
cators. Attached to the frame are adjustable guides, L and M, to 



CALENDERS 



99 



control of the width of the sheet of rubber. The upper and lower rolls 
are adjusted by vertical screws which obtain their motion from 
worms on the shafts Y and W, and from the bevel gears N and 
through the action of the hand wheel P. By a clutch either the fric- 
tion or the even gears are thrown in or out of engagement. The even 
gears R and S, as well as the friction gears T and U , are arranged on 
the same side of this machine. As a rule they are placed on opposite 
sides. 

Sta^^daed Foue-Eoll Calendee. 
Fie-. 89 illustrates a four-roll calender. The second roll from the 
bottom is the drive roll. The top and bottom rolls are adjustable by 




Fig. 89. — Four-Roll Calender — American Type. 



screws and worm gearing 



The third or next to the top roll is adjusta- 
ble by wedges above and below the journal boxes, by means of screws 
and w^orm e'earins:. 



100 



RUBBER MACHIXERY 



In American practice the rolls are geared so that the three lower 
rolls have even motion, and the three upper, friction motion. In 
European practice all four rolls are geared for both even and friction 
motion. The friction speed is about 1% to 1. 

The operation of the machine in coating is as follows : The 
rolls are warmed to the proper temperature. A roll of cloth is placed 
in bearings in front of the calender. The clutch is then thrown in, 
which puts the rolls in motion. A quantity of compounded stock from 
the warming mill is placed between the top and third rolls between 



r^ 


ws 

m 
1 


3 ^^^R5W 




i 

® 


m 

■I V 


1 






)md^m^$^m% 


3 




J^ * 






1 


•§ 




iE4 


s^ 


m 

1 


'^mmm 


li 


A 


{] ^ 


-1 


- 


r ^J 




llf^f^ 


^ 






e: 




V 









Fig. 90. — Four-Roll ExGRA\^xG Calender. 

guides set to the proper Avidth. This forms into a sheet around the 
third roll and the second roll where it is applied to the fabric. In some 
factories the coated fabric is wound upon drums which are sometimes 
10 or 12 feet in diameter, as this facilitates the later handling. It is 
a good idea to have a coating calender arranged for at least two speeds 
as some fabrics can be coated at double the speed of others. A good 
standard would be 10 yards a minute for slow speed and 20 yards 
for fast speed. About forty horse-power is required to run the machine 
described. 



I 



CALENDERS 



101 



The Matthew Calea^der. 

This is a small even motion or friction calender bnilt particularly 

for making strips, piping, bindings, etc. As shown in Fig. 91, the 

rolls A, B and C extend outside of the frame D while the reducing 

gears are placed between them. The rolls are driven at even speed 



f^T 




Fig. 91. — The Matthew Calender. 



or friction speed, as required, by the pinions G and H on the shaft /. 
Beside the rolls is placed a table P, over which the fabric is led. An 
adjustable guide is provided between the rolls B and C, so that the 
desired marginal width of rubber coating may be applied. 



The Steinhaetee Coatixg Calexdee. 
It is sometimes necessary to coat leather with rubber, and that 
is what Steinharter's machine is designed to accomplish. Referring to 
the diagram in Fig. 92, which shows the machine in section, the sheet 
of leather A passes over a guide B and under a wire brush C, which 
revolves at high speed and raises a nap on the surface of the leather. 
The leather then passes between two rolls D and E, one of which is 
heated to a temperature of 100 degrees F., and the other to 300 degrees. 
Directly above these rolls is a spout F leading from a tank containing 
a thin solution of rubber G. This is spread evenly over the surface of 



102 



RUBBER MACHINERY 




Fig. 92. — The Steinharter Leather Coating Calender. 

the leather and acts as a binder. The rubber is fed between the rolls 
E and H forming a thin sheet. This is calendered to the leather 
between the rolls D and E. 




Fig. 93. — -The Ackerman Calender Feed. 



CALENDERS 



103 



The Ackerman Calender Feed. 

In Fig. 93 is shown a calender feed which is in brief an endless 
belt carrier that delivers the rubber compound from the warmer to 
the calender, that exactly the right amount of rubber be thus delivered. 
The warmer sheets the rubber in the proper thickness and trims the 
edges of the sheet. 

The endless belt delivers the sheet over the top roll of the calender 
between the top and third roll where ordinary guides are provided, 
and so on to take off at the bottom. By using a number of knives in 
connection with the warmer, the sheet is delivered in the form of strips 
which are simultaneously calendered. A is an ordinary four-roll calen- 
der. D is the warmer. After passing around the roll E the sheet is 
trimmed by knives K placed on the horizontal shaft L. By means of 
set-screws the knives may be placed any distance apart. The sheet is 
carried by the endless pass belt N mounted on rolls P and Q driven by 
gearing from the main driving shaft. This belt is as wide as the calen- 
der rolls B. By a proper separation of the rolls E and F and of the 




Fig. 94. — The Whitlock Hydraulic Lift. 



104 



RUBBER MACHINERY 



first pair of calender rolls, the thickness of the sheet is such that it 
passes without distortion between the calender rolls. 

The Whitlock Hydraulic Lift. 
Fig. 94 shows a lift (used so far for paper calenders only) oper- 
ated by hydraulic cylinders placed at the top of each frame of the 
calender. In the illustration only one cylinder is shown. The frame A, 
containing two or more rolls has a hydraulic cylinder D cast integrally 
with cross piece E. The plunger F acts directly against the yoke G 
on which are two threaded rods H and K, which support yokes L and 
M which bear the ends of the rolls B and C. The cylinder is provided 
with a packing ring N and in which is cut a circular groove to allow 
the water to pass from the cylinder through holes R, to the overflow 
pipe P when the plunger is at the top of its travel. 

The Beswick Electrically Heated Roll. 
The calender roll shown in Fig. 95 is heated by electricity instead 
of by steam. In the illustration, A represents a portion of the frame 




Fig. 95, — The Beswick Electrically Heated Roll. 



of the calender, in which is mounted the shaft B. The heads C and 
D are mounted on this shaft and bear the roll E. Secured to the interior 
of C and D are electric insulators F which carry the iron wires G. 
These wires are arranged to follow the contour of roll E. On the outer 
surface of D are insulated conducting rings H and K connected with 
wires G. Attached to the frame A are insulated brush holders L 
carrying carbon brushes M. These brushes may be connected through 
N to the source of electrical energy R. The outer end of the roll 
beyond the head D is enclosed by swinging doors ;S', which permit access 
to the brushes. 



CALENDERS 



105 



The Hadfield Calender Feed. 
Hadfield's machine for carrying compounded stock from the 
warmer to the calender, keeping it warm, and incidentally dispensing 
with the service of one calender tender, is shown in plan view in Fig. 
96. At J. is shown a main frame upon which are mounted four calen- 
der rolls. The shaft H is provided with a guide roller / and a sprocket 
J, the latter transmitting motion to the feed rollers TJ. The shaft K 




Fig. 96. — The Hadfield Calender Feed. 

carries another guide roller L and a gear P which meshes with the 
idler gear M. Thus, when power is applied to the driving pulley, the 
rollers U are driven hy sprocket chains Q, R, S, etc. The conveyor 
rollers rotate upon steam pipes W and V which supply heat to them. 
From the warmer the rubber, in rolls about three feet long and five 
inches in diameter, is placed on the feed rolls U and delivered to the 
calender. 



The Dootsox Koll Lubricator. 
Fig. 97 shows an end section of a calender roll equipped with 
Dootson's lubricating bearing. This consists of bearing sections A 
between which are metal boxes B. The side next to the roll neck C is 
m.ade of metal gauze D. The box is filled with heavy grease and feeds 
through the gauze. Each box is lined with asbestos F to keep the lubri- 
cant from liquifying and has a door E for filling. 



106 ■ RUBBER MACHINERY 

The Claeemoxt Calek-der Gage. 
Fig. 98 shows a novel form of gage for measuring thickness 



sheets of rubber on the calender. A is a cylinder containing a rubber bag 



of 




. Fig. 97. — The Dootson Roll Lubricator. 

B, On each side of 5 is a piston, one of which is attached on roller C, 
the other to an adjusting screw E. From the bag B a graduated glass 
tube F projects above the cylinder. The sheet to be measured passes 
between the calender roll and the roller C, the liquid in F, being set at 
zero by the screw E. As the sheet comes against the roller the piston 




Fig. 



-The Claremont Calender Gage. 



compresses the liquid in the cylinder and forces it up in the tube. The 
apparatus is very sensitive and a slight variation in the thickness of the 
sheet is accurately recorded in the tube by the change in the height of 
the liquid. 



CALENDERS 



107 



The Coulter Spreader Bar. 
The device shown in Fig. 99 is an angle or Y-shaped spreader 
bar applied to calender rolls. Its office is to spread the rubber before 
being run into a sheet between the rolls. The drawing shows a sectional 
view looking toward the ends of the rolls A, B and C. The face of 
each spreader bar D conforms to the periphery of the rolls and the 
spaces K between them and the rolls are adjusted by the hand wheels E. 




Fig. 99. — The Coulter Spreader Bar. 



The spreader bars are hollow, to allow them to be heated or cooled. To 
control the width of the sheet, adjustable width-gages G are mounted in 
dovetailed slots at each end of D. 



Separate Wixd-Up Cooling Roll. 
It is often desirable to wind up the coated fabric as it comes from 
the calender, by means of a separate roller set a short distance 
away, instead of on the wind-up roller usually fixed to the calender 
frame. The stand shown in Fig. 100 is designed for this purpose. 
It is equipped with a cooling roll A and stretcher E set on cast 



108 



RUBBER MACHINERY 




Fig. 100. — Separate Wind-Up Cooling Roll. 



iron frames. The cooling roll is a seamless brass tube 12 inches in 
diameter, with cast iron heads and water connections. The roll is 
driven by a flanged friction pulley B. By the hand wheel C, the roll 
can be adjusted to give the proper amount of slip. Above the cooling 
roll are two wooden rollers D (only one being shown) for passing the 
fabric over the cooling surface. The stretcher E consists of two rollers 
set at such an angle to each other that they remove the wrinkles from 
the fabric as it is wound. 

GrAMMETEK StOCK ShEEL. 

The Gammeter stock shell shown in Fig. 101 is a metal roller for 
winding up stock as it comes from the calender. It is made with thin 
steel walls and is open at the ends so that air may circulate through it. 
The shell A is riveted to iron supporting rings B, the end rings having 
square openings in the hubs for the mandrel. A square tube C connects 
the two end frames so that the mandrel may be easily slipped through 
from one end to the other. A slot D extends along one side of the shell, 
into which a metallic strip is slipped. Attached to this is a fabric apron 
E, extending almost around the shell and used for holding the end of 
the calendered sheet when starting to wind it up. One complete revolu- 
tion of the shell causes the apron to close down upon the stock, tJius 
permitting tension to be applied to wind smoothly and without slipping. 



CALENDERS 



109 



The Bowen Roll Geindee. 

Figs. 102 and 103 show a somewhat complicated machine for 

grinding calender rolls with straight or crowned surfaces. It has two 

grinding wheels located on opposite sides of the machine frame so that 

both sides of the roll are worked upon simultaneously. The roll with 




Fig. 101. — Gammeter Stock Shell. 



its journals is placed in the bearings A, the end being fastened to the 
coupling head B of the driving shaft C, which is driven by the pulley D, 
The emery wheels E move horizontally along the face of the roll on the 




Fig. 102. — The Bowen Roll Grinder. 



110 



RUBBER MACHINERY 




Fig. 103. — Section Through the Bowen Roll Grinder. 



screw shaft F. This is accomplished automaticallv as the grinder 
reaches the end of the roll, throngh a lever and a spring con- 
trolled rod H connected with the clutch quadrant. In the end view of 
the machine it will be seen that the grinder carriage I I is arranged to 
slide in grooves / -/ in the bed. Running through this carriage, from one 
side to the other of the machine, is a shaft K which bears a hand crank 
L at each end and is geared to an adjusting screw M bearing hand wheels 
N. It is by means of these screws that the plates 0, upon which the 
grinding wheels are mounted, move toward or away from the roll. If 
considerable movement is desired, the screws M are turned directly by 
one of the hand wheels N, while for fine adjustment, either of the hand 
cranks L is used. When one screw is turned the other screw on 
the opposite side of the machine will be turned the same amount and 
in the same direction, so that the carriers on both sides are simul- 
taneously adjusted. 

The holder of each grinding wheel is pivoted on its carriage 
at P and the grinders are driven by belts Q from an overhead shaft. 
This allows them to be moved around the pivots as centers Avithout 
slackening of the belts. The rod Y operates a lifting arm TT and this 
rotates the crank shaft X which raises or lowers the grinder. By setting 



CALENDERS 



111 



the block on the lower end of the rod V on one side of the center of 
the link T, the grinders will cut a convex surface, 
opposite side will give a concave cut. 



while setting on the 



The Linton Roll Grinder. 
The Linton machine, shown in Fig. 104 grinds calender rolls 
without taking them out of the frame. A is a shaft upon which the 
emery wheel B is shown in position. Pulley G is driven by a belt from 




The Linton Roll Grinder. 



pulley D. This pulley is mounted on a threaded sleeve on the screw 
shaft E. The appliance is driven through pulley F by the belt G which 
runs over the neck of the calender roll. This drives the drum H and 
through the belt K and the pulley D, the emery wheel B. The pulleys 
I and / drive loose pulleys L and M on the end of the screw shaft E , 
through belts N and respectively. These pulleys may be made to 
drive the screw shaft fast or slow by engaging a clutch through the 
lever P. A fine or a coarse cut is given by regulating the distance of 



112 RUBBER MACHIXERY 

the shaft A from the rolls, by means of screws R acting on the adjust- 
able bearing blocks aS. 

In an earlier machine invented by Linton, the grinding wheel 
was loosely mounted on a tubular shaft which contained the screw shaft, 
access to which was through a slot cut the entire length of the tube. 
A pin in the hub of the gTinding wheel engaged the screw through 
the slot, so that it traveled along the rolls of the calender much as in 
the machine described above. 



i 



CHAPTER VII. 

CLUTCHES, DRIVES AND SAFETY STOPS FOR MILLS AND 

CALEISTDERS. 

The mechanical appliances for stopping and starting mills and 
calenders broadly known as clntches, are found in great variety and 
are most important. To operate these instantly in case of accident 
a great number of safety stops have been invented. When one is on 
the subject of clutches and safety stops it is natural that the drive, 
electrical or other, be considered. That brings up the question of 
variable speed and calender and mixing room arrangement. All of 
the above topics are reviewed in the following pages. 




Fig. 105. — The H. & B. Friction Clutch. 

In the olden time the form of clutch universally used was the 
jaw clutch. Today it has been almost wholly superseded by friction 
and magnetic clutches. 

In many rubber mills much of the power exerted in driving the 
gearing is wasted by the main shafting being kept in motion while a 
part or all of the machines are at rest. Where individual electric drive 
is not employed the remecl}^ for this is the adoption of friction clutclies 
located at different points throughout the mill. They not only effect a 
saving in power but may be the means of avoiding serious accident by 
permitting prompt stopping of the main shaft or of individual machines. 

The H. & B. Friction Clutch. 
A friction clutch for driving calenders and grinders is shown in 
Fig. 105. A is the driving shaft. B, C and D are inner integral parts 



114 



RUBBER MACHIXERT 



of the clutcli, keved to the shaft A and revolviiia' Avith it. On the left 
is shown the rim D split at E and E, and right and left hand screws 
F F which are connected bv levers L L to the slidins; sleeve M. The 
outer casing N and the hub of the clutch are integral and revolve 
on the shaft A. 

In operation, the part B^ the levers L and the sliding sleeve M 
revolve with the shaft A. The casing X, 0, is keyed to the gear or 
pulley of the machine to be driven and is loose on the shaft A. The 
clutch is operated by a lever which forces the sliding sleeve M toward 
the clutch. The levers L L turn the right and left hand screws F F , 
which expand the rim D against the inner surface of the casing N , 
causing it to drive the machine. 

The Yaughx Fkictiox Clutch. 

Fig. 106 shows a multiple-band friction clutch. It is of the bal- 
anced coil type. The principal members are two steel coils and a 
chilled iron drum. The coils are controlled bv two semi-circular 




Fig. 106. — The Vaughn Friction Clutch. 



CLUTCHES', DRIVES AND SAFETY STOPS 



115 



shoes which contract on the tail end. When the clutch is in action, 
the shoes are drawn up to the coil by the toggle. 

This clutch provides an effective safety stop, as the coils release 
from the drum instantly. The comparatively small diameter eliminates 
momentum, brakes being unnecessary. The toggle action is such that 
when the clutch is engaged it is locked in position, requiring no pres- 
sure to hold it. The handwheel controller is equipped with a safety 
trip, which is mechanical and positive in action. If desired, it can be 
operated from push buttons located at convenient points. 

The Goedox Pneumatic Clutch. 

In Fig. 107 is shown a pneumatic multiple disc clutch connecting 

two shafts. It consists of a circular casing A keyed to the driving shaft 

B. In the casing are twelve friction discs E and F arranged alternately. 

Six of these are fastened to the casing A and six to the hub which is 




The Gordon Pneumatic Clutch. 



keyed to the driven shaft D. G is a circular piston which acts against 
the discs. C is a cover bolted to the casing A turning on the shaft D. 
The clutch is operated by air or water under pressure admitted at N, 
passing through the opening J and forcing the piston and the discs 
tightly together. This transmits the motion to the driven shaft. 

Magnetic Clutch. 
A type of magnetic clutch that not only couples the driving to 
the driven shaft but also has an automatic brake which acts when the 
current is interrupted is shown below. One objection to the magnetic 



116 



RUBBER MACHINERY 



clutch was that the time between the opening of the operating coil 
circuit and the releasing of the coupling was small and practicallv 
negligible under a full load but large under a light load. Another 
objection was that they did not engage gradually but took hold almost 
as suddenly as a jaw coupling. 

The first objection appears to have been overcome by an automatic 
band brake on the mill side of the cut-off coupling and the other by 
the Cutler-Hammer accelerator clutch. 

Maoxetic Clutch with Ai'tomatic Baxd Brake. 
Fig. 108 shows two views of this clutch equipped with an auto- 
matic band brake. The driving part of the clutch or field A carries 
the magiietizino' coil B. It has a hub D which is keved to the drivino^ 




Fig. 108. — Magnetic Clutch with Automatic Band Brake. 

shaft. The armature or driven member G has a similar hub E which 
is keyed to the driven shaft. Attached to ^ is a flexible spring steel 
plate G which carries the armature G. A friction facing H prevents 
the armature from coming directly against the face of the coil and 
<nlso provides frictional contact for driving. This friction facing is 
woven asbestos and brass wire similar to brake lining On the hub I) 
are two insulated contact rings / which are attached to the ends of 
the magnet winding B. This is supplied with current by contact with 
a pair of brushes K, from the source of power. Attached to the driven 
shaft is a brake drum L with a brake band M of the same material 
as the friction facing H. The ends of the brake band are pivoted at 
N and to a lever P, which carries an adjustable weight Q at its outer 
end. Xear the center of this lever is pivoted a vertical rod R attached 



CLUTCHESl DRIVES AND SAFETY STOPS 



117 




Fig. 109.— Magnetic Clutch and Brake with Flexible Coupling. 



to a solenoid in the cylinder ;SI, The solenoid raises the lever P when 
the circuit is closed, thus loosening the hrake band. 

The operation is as follows: The current is gradually applied to 
the magnet coil by means of a rheostat. As the current increases in 
the coil the flexible steel plate containing the armature is pulled toward 
the coil. The friction gradually increases between the armature and 
the friction facing until the current is strong enough to rotate the 
driven shaft at the same speed as the driving shaft. The current 
applied to the magnetic coil energizes the solenoid and lifts the weighted 
lever allowing the brake drum to run free. Rod T serves to hold the 
brake band in circular form when the brake is released. 

In case of accident the switch is thrown by a rod or lever con- 
veniently placed, thus breaking the circuit. This also interrupts the 
solenoid circuit, allowing the lever P to drop and tightening the band 
around the drum. Thus it will be seen that in addition to shuttinic 



118 



RUBBER MACHINERY 



off the power the brake is applied the instant that the two shafts are 
iinconpled, bringing the mill to a quick stop. 

Mag^^etic Clutch and Beake with Flexible Coupling. 
A combination magnetic clutch, brake and flexible coupling is 
shown in Fig. 109. In this the armature A is carried by a roller bear- 
ing B on an extension C of the power shaft. Connection is made be- 
tween the armature and the brake wheel D, which is carried by the 
mill line shaft E, through a flexible coupling. This is a cylindrical 
extension F on the flange carrying the brake wheel. These extensions 
are slotted and encircled by a rawhide band G. A flange H projects 
into the annular slots and serves to transmit the power. This coupling 
is sufficiently ffexible to permit the driving and driven shafts to be 
out of level as well as out of alignment. The 60-inch clutch has a 
normal rating of 450 horse-power at a speed of 90 revolutions per 
minute. 

Clutch and Brake Installation. 
Fig. 110 shows the installation of the magnetic clutch described 
above. The shaft of the motor A carries the driving member B. The 




Fig. 110. — Clutch and Brake Installation. 



end of the driven shaft C carries the armature D. When the clutcli 
is disengaged the two shafts are independent of each other. The shaft 
C also carries the automatic brake E which is applied when the clutch 



CLUTCHES, DRIVES AND SAFETY STOPS 119 




Fig. 111. — Magnetic Clutch and Brake Assembled. 

circuit is broken. The mill shown at F is driven from the line shaft 
G through the pinion H and gear I, 

Deives foe Calei^dees. 

The means for driving calenders may be considered as a separate 
subject since, by the installation of proper gearing, any method of 
drive may be employed. Formerly, calenders were driven by steam 
engines from line shafts, but in recent years this form of drive 
has been gradually superseded by the electric motor. Usually the 
speed of the motor is reduced with one pair of gears in addition to the 
calender driving gear and pinion, but it is sometimes necessary to use 
two pairs owing to special conditions. 

Two-Speed Deive. 

In Figs, 112 and 113 are shown a plan and elevation of a two-speed 
drive with a double friction clutch mounted on the main shaft. The 
pinions A and B are mounted on loose sleeves on the driving shaft C. 
The outer casings of the clutches D and E are also mounted on these 
sleeves and turn with the pinions. The splined sleeve F turns with 



120 



RUBBER MACHINERY 




Fig. 112. — Two-Speed Drive. 



the shaft and is moA^ed in either direction by the hand wheel G, the 
segment rack H and a yoke on the shaft K. By turning the hand wheel 
G to the right, the sleeye F moyes to the left, engaging the clutch B 




Fig. 113. — Elevation of Tv^o-Speed Drive. 



CLUTCHES^ DRIVES AND SAFETY STOPS 



121 



and driving the pinion A, gear L and pinion M of the machine. Since 
the pinion A is larger than B, this engagement provides the higher 
speed. If the lower speed is required^ the hand wheel is moved in 
the opposite direction, engaging the clutch E and the gears B and N, 

Theee-Speed Drive. 
The triple friction clntch drive, in Fig. 114, is one of the methods 
of obtaining different speeds before the general adoption of electric 
drives. The driving shaft, which runs at a constant speed, carries 




Fig. 114. — Three-Speed Drive. 



three friction clutches attached to gears. Each of these gears engages 
with pinions on the calender driving shaft. These gears and pinions 
give three speeds and the change from one to another is made by throw^- 
ing in the proper clutch. 

Electric Calender Drive. 
Eig. 115 shows a typical electric drive with one pair of reducing 
gears. The motor A is set on a separate foundation plate B. Its 
shaft bears the pinion D which engages the large gear E. This is 
mounted on the shaft F with the calender pinion G. The electric con- 
troller for starting and stopping the motor takes the place of a clutch. In 
the installation shown, the motor is a slow, variable speed type on 
account of the slow speed of the calender and the small gear reduction. 
Individual electric drives furnish variable speed controls. With these 
a calender can be run fast or slow by operating one of several switches. 



122 



B UBBER MA CHIXEB I 




Fig. 115. — Electric Calexder Drive. 

It is estimate':! that three motor driven calen<;lers Avill ttirn otit the 
same amiijiint nf wruk as four calenders driven from a line shaft. This 
is due to the wider range of speed, the time saved in changing from one 
speed to another, and the alhlity to nm the calender at the highest prac- 
ticalile speed for each kind of stock. Calenders are driven by either 
direct rir alternating current motors, and stich drives for all classes of 
machines and for all kinds of work have l>ecome standardized. 

In this connection, what C. A. Kelsey has written is of special 
interest. 

■^■'The power required to drive a calender varies over a wide range. 
depending on the character of the componnii. thickness, width and 
speed. The speed is limiteif to that at which the componnii can be rim 
without blistering or the forming of a rough surface. When the cal- 
ender is started np with cold rolls the permissible speed is higher than 
after the cooling rolls become heated. As these rolls become heated, 
it is necessarv. in order to obtain the desired surface of the sheet, to 



From "Electrical Requirements of Certain Machines in the Rubber Industry-," by 
C. A. Kelsey — Proceedings of the American Institute of Electrical En- 

g-ineers, Tulv, 1913. 



CLUTCHESl DRIVES AND SAFETY STOPS 123 

Teduce the speed. A fine speed graduation is therefore necessary to 
maintain a maximum output. The torque required depends upon the 
thickness and material and there are so many combinations possible 
together with the speed requirements that it is difficult to formulate 
any rule to determine the power. The motor must be large enough to 
meet the extreme conditions. 

''From a number of tests made, it is found that an 18-inch (45.6 
■cm.) diameter, 40 inch (1 meter) face, three-roll calender running at 
a surface speed of 37 feet (11.2 m.) per minute, requires an average 
of 20 h. p. A 24-inch (60 cm.) diameter, 48-inch (1.2 m.) face, three- 
roll calender running at a surface speed of 35 feet (10.6 m.) per minute 
requires an average of 35 h. p. and a 22-inch (55.8 cm.) diameter, 
65-inch (1.64 m.) face, three-roll calender running at a surface speed of 
36 feet (10.9 m.) per minute requires an average of 45 h. p. 

''Some compounds that are run through the calender in successive 
layers which build up to l/2-inch (1.27 cm), or even %-inch (1.9 cm.) 
must be run at approximately 20 feet (6m.) per minute, while for 
friction work the speed of the driven roll may be 80 feet (24.3 m.) per 
minute. The thick sheets will require slightly greater torque than the 
average thickness while the torque for so-called friction work is consid- 
erably less. 

''As the compound and fabric are fed through in a continuous 
sheet the power required for a given material, thickness and width is 
quite uniform. 

Motor Characteristics. 

"In considering the power and speed requirements of the different 
machines, it is seen that the mills for working up rubber and mixing- 
it to form the various compounds, call for extreme overloads, but of 
short duration. By grouping these mills and driving by a single motor 
the load peaks can be reduced. Instead of the maximum values being 
200 per cent, of the average, it has been determined that this can be 
reduced to 150 per cent by driving w^ith one motor a group of six mills 
used for masticating, mixing and warming. 

"Where individual drive is used, alternating-current polyphase 
squirrel cage motors are best suited to carry the high load peaks. By 
grouping the mills, a motor of smaller capacity than the aggregate 
of the individual motors can be employed. Moreover, synchronous 
motors can then be installed and assist in correcting the power factor 



124 RUBBER MACHIXERY 

of the general power load. The mills are generally equipped with jaw 
cliit<ihes which can be open or closed while the shaft is running. The 
s^Tichronous motor can thus be disconnected from the mills at start- 
ing. The selection of squirrel cage or woimd rotor induction motor 
depends upon the local starting restrictions, as the squirrel cage motor 
will easily bring the shaft up to speed even with all mills connected. 

"Direct-current motors are sometimes used when this is the power 
available, but they are more expensive and not so well suited to the 
load conditions. 

''The calenders, as mentioned, require close speed control over a 
range four to one. This can best be accomplished by a direct current 
motor, which is the general practice. A number of schemes have been 
employed to accomplished this. Among them might be mentioned the 
multi-voltage and adjustable voltage methods. The motor is excited 
at constant field strength and the armature supplied with a variable 
voltage. This variable voltage can be produced by a series of different 
A^oltage generators or by a rotary compensator or booster set. 

''A modification of the preceding is a three-wire, two voltage source 
of armature supply combined with adjustable speed by field control. 
The first mentioned methods produce a wide speed range but are 
expensive because of the number of machines required for each calen- 
der. The second method produces a less speed range but is less expen- 
sive, particularly where a large number of calenders are installed. With 
the more recent general application of commutating poles to direct cur- 
rent motors a gTeater speed range is permissible with constant armature 
voltage and varying field strengths. 

'This last mentioned method results in the simplest equipment as 
a whole. The motor must be larger but is therefore more substantial, 
while the control can be made extremely simple, or it can be made 
entirely automatic, thus calling for the minimum of attention and care 
from the operator. 

"As the power to drive the mills is by far the greatest portion of 
the total power, alternating current will generally be selected. This 
therefore requires a motor generator set or a s;Nmchronous converter to 
deliver current to the calenders. The machines can be used to correct 
the power factor of the general power circuit. 

Motor Coxteol. 

"As the motors to drive the mills are run at constant speed, onlj 
starting devices are required. A speed controlling device must, how- 
ever, be furnished with the motors driving calenders. The calenders- 



CLUTCHES, DRIVES AXD SAFETY STOPS 



125 



require close attention and must be capable of starting and stopping 
by the simplest means on the part of the operator. This is best met 
bv a control which enables the operator to bring the calender up 
to the speed by moving the controller handle around to obtain the desired 
speed. Automatic acceleration should be provided to limit the current 
input while the controller handle is being moved around. It should 




Fig. 116. — Motor Calender Drive. 

then be possible to shut the calender down by pushing a button located 
on the calender. The speed of the calender should be retarded by d^Tia- 
mic braking of the motor. This is to provide a safety feature in respect 
to the operator in case his hand should be caught between the rolls. 
Also it is desirable to stop quickly to save material otherwise wasted 
by the coasting of the motor. It should then be possible to bring the 



126 



RUBBER MACHINERY 





i \w 


^ "-J ■■-■ 


^^^^P^B^^4»« 


1 


^^' ' ^^■^^w 


n 




tm^ ^-1 




1 




i 




1 -* ^ 






fi 


m 


•^^-^ TiiiliiiiiiiilifaL. .^_^^ 


•^ 



Fig. 117. — Westinghouse Motor Driven Calexder. 



calender up to the game speed as before by pushing a button on 
the calender. Means should be provided for reversing the direction of 
rotation of the motor to assist in manipulating the calendar and also in 
case anything should be caught between the rolls and it becomes 
necessary to back it out. The control should also include overload and 
low voltage release features and be immxune from damage to itself or 
the motor, in case the operator fails to close or open the proper 
switches." 

MoTOE Calexdek Deive. 

Fig. 116 illustrates a Vaughn three-roll calender equipped with 
a Westinghouse control. The calender is direct connected to a variable 
speed motor through cut herringbone gears. The drive is located under 
the floor. The controller has a number of maonetic switches, relavs 
and resistances for automatic acceleration, overload and low voltage 
protection and dynamic braking. A master controller of the drum 
type is provided and the calender is always in full control of the 
operator. Push buttons are located at convenient points so that the 



CLUTCHES^, DRIVES AND SAFETY STOPS 



127 



motor can be stopped almost instantly. A large number of running 
points are provided so that variations in speed may be obtained at 
the will of the operator. 

Safety Stops. 

Workmen employed on calenders and mixing mills are sometimes 
caught in the rolls, the result being disastrous, perhaps fatal. The 
ordinary clutch mechanism is so far from the workman that it is 
impossible for him to reach it in case of accident. The safety stop 
provides a throw-out within easy reach and can be operated by the hand, 
foot or even head or shoulders. 

Automatic CLrTCH Thegw-Out. 

Figs. 118 and 119 show a simple form of clutch throw-out. It 
consists of a pinion and clutch, the latter being made with a helical 
shoulder on the inner face. A steel doff is held above the clutch bv 
a latch attached to a light chain carried over pulleys above the mill, 
terminating in a handle above the rolls. Instead of the handle, a bar 
placed horizontally across the frame is often used. A slight pull on the 
chain raises the latch and releases the dog which falls into the open- 





FiG. 118. — Clutch Engaged. Fig. 119. — Clutch Thrown Out. 

AuTo?»iATic Clutch Throw-Out. 



128 



RUBBER MACHINERY 



ing between the flange on the pinion and the clutch. As the main 
shaft revolves the steel clog forces the clutch out of engagement, stop- 
ping the machine. 



Forsyth Safety Stop. 
The Forsyth safety device is shown in Figs. 120 and 121. Acros:^ 
the top of the rolls, in a position readily accessible, are two levers, A and 




Fig. 120. — Forsyth Safety Stop. 



B pivoted at C and D to the frame of the machine. They are pivoted 
together and swing loosely on their pivots. The arm B has on its hub 
D a hook G which, in its normal position engages a lug II on the 
sleeve /. This sleeve slides on the arm J and supports a weight K 



/Ql. 




Fig, 121. — Details of Forsyth Safety Stop. 



CLUTCHES^, DRIVES AND SAFETY STOPS 



129 



attached to the chain L, the end of the arm / resting npon the bracket 
M. The chain L passes over the pulley X and is connected to a sec- 
ond chain 0. This is connected with the shipping lever Q which 
operates the friction clutch S. Xormally the parts remain in the posi- 
tions shown. In case of emergency the lever B is pushed back, throw- 
ing over the hook G and releasing the slide I. The weight then falls 
and pulls the lever over to the left, disengaging the clutch and stopping 
the machine. 

The Faeeel Ron Teip Theow-Out. 
Another safety device is the Far r el rod trip throw-out, Fig. 122. In 
this the latch trip A is released when the horizontal rod B is forced 
forward or back. This allows the heavy steel dog C at the lower end 




Fig. 122. — Farrel Rod Trip Throw-Out. 



of the chain D to fall into the opening between the clutch E and the 
pinion flange F which forces the two members of the clutch apart, stop- 
ping the machine. As an additional precaution this device sometimes has 
a foot lever located near the base of the machine for tripping. 



130 



RUBBER MACHINERY 



The Bikmi^^gham Safety Stop. 
The application of a pneumatic clutch as a safety stop is shown 
in Fig. 123. The casing A is bolted to the driving gear B which is 
loose on the neck of the roll C. Keyed to the inside of the casing is 
a set of friction discs. These alternate with another set fastened to 
a hub that is keyed to the outer neck of the roll C. A circular piston 
located in the casing A and of similar shape, is forced against the discs 
by air or water under pressure admitted through the operating valve D. 




Fig. 123. — The Birmingham Safety Stop, 

This valve has inlets E and F and an outlet G. When the rod H is 
in its lower position as shown, the outlet is closed and the air or water 
passes through the pipe I and forces the piston back, which engages 
the discs and starts the mill. When the cross bar L and the arms K 
are pulled down the chain M raises the rod II and stops the machine. 



The Dodg-e Safety Stop and Bkake. 
Fig. 124 shows a side elevation of a friction clutch with an auto- 
matic brake. The outer casina;^ A is keved to the drive shaft B and the 
inner casing C is keyed to the mill shaft D. The clutch is operated 
by hand wheel F, pinion and segment rack G and levers H. In case 
of emergency the cord or bar over the machine is pulled, releasing the 



CLUTCHES, DRIVES AND SAFETY STOPS 



131 




Fig. 124. — The Dodge Safety Stop and Brake. 

weight /. This engages the pins / with the lugs K, which raises the 
lever L and applies the brake on 0. 

Variable Speed Belt Drives for Cale^s^lers. 
Many forms of variable speed devices are in use in rubber mills' 
and the machine for which they are best adapted is the calender. 
Where only one or two definite speeds are required, the ordinary reduc- 
ing gears equipped with proper clutches are best. On the other hand, 
where a great number of speed changes are required, it is desirable 
to employ friction driving devices. 



Tile Evans FRiCTiorsT Drive. 
A well known type is the Evans, shown in Fig. 126. The driv- 
ing cone .1 and the driven cone B have parallel axes, but are separated 
from each other by an endless friction belt. This is moved between 
the cones by the chain D, and thus the speed of the driven shaft may 
be varied. The two cones forced together press against the friction 
belt. In the overhead apparatus this is done by a lever C similar to the 
ordinary belt shipper and is used to start and stop the machine. 



132 



RUBBER MACHINERY 




Fig. 125.— The Krupp Safety Stop. 

Reeves Variable Speed Transmission. 
The device shown in Fig. 127 has hangers cast integral with the 
frame and can be fastened to the floor or ceiling. The two cone 
shaped discs C C are spline monnted, with their apexes facing, on 
the drive shaft A. Another pair are similarly mounted on the driven 
shaft B forming a groove for the endless V-belt. These discs slide 
freely on their shafts but rotate with them. They are moved toward 
or away from each other by the levers D D, pivoted at G (7 and operated 
by a right and left screw. The speed of the driven shaft is varie*] 
by turning this screw to the right or left. This is done by gears E 




Fig. 126.— Evans Friction Drive. 



CLUTCHESl DRIVES AND SAFETY STOPS 



133 




Fig. 127. — The Reeves Variable Speed Transmission. 

and a straight or cross belt on the tight pulley F, driven from shaft A. 
In the illustration the discs on the driving shaft are shown operating 
the shaft B at the minimum speed. 



The Bixby Variable Speed Drive. 
A plan view of this device is shown in Fig. 128. The hangers 
C C, support two parallel shafts E and G upon which are mounted 
cone pulleys A and B. The shaft G is mounted in hangers which 
swing on the shaft R journaled in the hangers C C. The cone pulley 
B swings away from A and by gravity tightens the cone belt L. Bolted 
to the bottom of the rigid hangers is a guide bar I on which slides a 
yoke -/ bearing two vertical rollers K K. These project between the 
cone pulleys, spanning the lower part of the belt L which is shifted 
by a cable M that passes over sheaves N. The adjustable weight P 
is mounted on the lever Q fixed to the shaft R. This forces the pulley 



134 



EUBBEE MACHIXEEI 




Fig. 128. — The Bixby \'ariable Speed Dri\-e. 

B away from A and tightens tlie belt. The belt H dri\'es the shaft G 
and the cone pulley B and the belt L transmits the variable speed to 
the cone pnlley A and the shaft E. 



A Model Calexdee Eoo^i Plax. 

Pig. 129 shows a typical layout of a modern calender and mill 
Toom."^ The main features are taken from the calender room of an 
existing rubber factory and are applicable to almost any sized installa- 
tion. 

The room is 75 feet wide bv 150 feet long, with a 1%-inch maple 
floor laid on concrete. On either side of the room is located a line of 
six mills with 20 by 60-inch rolls. Pach line is driven by a 300 
horse-power motor, with reducing gear, located midway bet^veen the 
mills, there being three on each side of the drive. Located between 
the mill lines are twelve 3-roll calenders, with 24 by 66-inch rolls, 
equipped with individual motor drives. A central passageway, 8 feet 
wide, extends the lenath of the room. 



* "A Model Calender Room," by Morris A. Pearson, India Rubber World, 
December, 1912. 



CLUTCHESl DRIVES AND SAFETY STOPS 



135 




136 RUBBER MACHINERY 

The drive is with the motor located directly over the line shaft, 
where it is easily accessible. Power is transmitted from the motor 
to the line shaft by cut double helical gears enclosed in oil-tight cas- 
ings. The only part of the drive to extend beloAv the floor is the lower 
part of the gear casing. 

The motor is connected with the reducine; o;ear bv a magnetic 
coupling and safety stop, which is operated by hand or foot trips from 
any mill on the line. A magnetic brake used with this coupling is 
automatically applied when it is cut off. The power required for 
energizing a 300 horse-power magnetic coupling is only 2 amperes at 
120 volts, and for the brake 1.75 amperes at 120 volts — both working 
continuously. It will thus be seen that the operating cost is compara- 
tively nothing. 

All line shafting is 6% inches in diameter and is located high 
enough to allow everything connected with the mill line to clear the floor. 

The calenders have individual drives, each machine being driven 
by a To horse-power variable speed direct current motor. The motor 
speed has a variation of 1 to 3 and permits a delivery on the calender 
of from 5 1-3 to 16 yards per minute when running friction and from 
8 to 24 yards per minute when running even. The motor controller 
is connected with a rod trip, located in front of the rolls, for emer- 
gency use. 

The Bitterlich Caeexder Koo:\r Layout. 

The calender room plan shown in Fig. 130, is a modification of 
Pearson's and embodies several special features. This is designed for 
the most economical production from an operating point of view. It 
should, however, be borne in mind that it would not hold good for 
all classes of rubber mills, since the sizes of calenders and mills and 
the processes of manufacture vary. 

It must be kept clearly in view that materials in process of 
manufacture should move in one direction to and from the machines, 
in an orderly manner, and without waste of time and energy. 
The essential features are as follows : — 

1. The calenders are located near the windows and the mills 
nearer the middle of the room. The process of calendering, dealing 
with the product in a more finished stage, demands the best light, while 
the function of the mill is merely to warm and soften the gum. 

2. The mills and calenders are placed as near to each other as 
is practicable, to reduce to a minimum the distance traveled in deliver- 
ing the batch of gum to the calender. In minimizing this distance it 



CLUTCHES, DRIVES AND SAFETY STOPS 



137 




/ 



1/ 



ii 



m 






tl 



4 



II 



ik 



/ 



m 




Si 



•f »t/>fff>f>ifn fff*' ^' 



r / r , /-r, , • I , , , ,/ , , , f / / r I , I Af , , , , , r f , r , f f , , , 



yt// CO fenders 24^60--^ Ko//. /I// Mi Ik ^O"^ GO." 

(^u/77. /yahric. /^/n/shec;/ f^oc/uct 

Fig. 130. — The Bitterlich Calender Room Layout. 



is necessary to lengthen the distance which the fabric and finished 
product travels. The latter are, however, delivered in larger quantities 
than the rubber batches and therefore have a less number of journeys 
to make. 

3. The central portion of the room is devoted to the storage of 
mixed gum. This allows piling the gum as high as practicable, with- 
out obstructing the light, and since rubber is affected by light, it should 
be stored in the darkest part of the room. While some light may be 
available from a saw-toothed roof with a single story building, it is 
desirable to obtain all the daylight possible at the calenders from the 
sides and from above. 

4. The building should be of one story about 20 feet high, 
equipped with a roof of sawtooth construction and spanned by a crane 
the entire width of the building. This would allow quick removal 
of rolls, frames and all other heavy parts requiring renewal and repairs. 
With the mills in the middle, the shafting should be below the floor. This 
can be arranged by building a tunnel, or better still, a basement, and 
carrying the foundations of the machinery to the floor below. Then all 
steam and water pipes would be located in this basement. 



CHAPTER YIII. 

::\roLDS. metal axd eubbee. 

MOST of the molds used in the manufacture of rubber goods are 
made of iron or steel. Soft metal molds are. however, used to 
an extent, especially in hard rubber work. For special work 
miolds have in the past been carved from blocks of soapstone. Their value 
over metal molds, however, is not apparent. Molds of plastic 
composition are also used in dental and stamp work. The strips of 
cloth wound about hose or tires to keep them in shape while curing, as 
well as the beds of French talc or soapstone in which goods are 
buried, are really molds. In a word, almost all rubber goods, except 
clothing and dipped goods, may be classed as molded work. 

Molds made of rubber are also often used. They are sheets of vul- 
canized rubber upon a fotmdation of heavy duck, the face of the rubber 
bearing the design that is to be transferred, say to a mat or tread. 
Such molds have a supporting edge of fabric and rtibber aroimd the 
edges, or are set on an iron plate with supporting edges. 

Rubber molds are made after a German formula that calls for 25 
parts of rubber in sohition and 75 parts of white of egg. After the 
solvent has been evaporated, enough sulphur is added to ensure vul- 
canization. The product is said to be full of nerve and to stand much 
wear. 

Rubber molds are also used in lines of manufacture other than rub- 
ber. For example, in shaping celluloid in certain work rubber vacuum 
bags are employed. In pattern making, in candy manufacture and in 
the molding of a variety of plastics such molds are often tised. 

The molds used in rubber manufacture are close molds. That is, 
they consist of two or more parts accurately fitted together and are 
lined up with dowel pins or giiides. The parts when placed together 
form an exact positive of the article to be manufacttired. 

Metal molds are generally made by a manufacturer who is a spe- 
cialist in this industry. Strictly speaking it is a part of the die maker's 
art and requires expert knowledge in the designing and skilled 
mechanics in the making. Many molds are made by the rubber manu- 
facturers in their own machine shops, particularly in mechanical and 
hard rubber work where a great variety of patterns are used. There 
is such an infinite variety of rubber molds that only a general descrip- 
tion of the methods used can be oiven. 



MOLDSl METAL AND RUBBER 139 

Many molds are made bv simply running plates of iron through 
a planer. Others call for engraving or die sinking in metal plates. In 
others the first step consists in obtaining a perfect reproduction of the 
object to be molded. This is turned up from wood or made from an 
original. From this a matrix is made of a plastic substance such as gutta 
percha, wax or plaster of paris. This matrix comes from the model in 
two pieces, each a perfect reproduction or intaglio of one half of the 
ariginal model. These two parts are then treated as patterns from 
which sand molds are cast in iron or soft metal. The final molds are 
then machined and accurately fitted together and provided with dowel 
pins or guides so that the mold can be separated and put together again 
in perfect register. In very small articles the impressions are duplicated 
several times and plate molds containing several dozen matrices are 
made. This type of duplicating mold is limited in weight as it should 
not be too heavy to handle from the bench to the press. 

Another method is to make the matrices thin or shell like and 
enclose them in cast iron or other metal. The advantage is that when 
the mold becomes worn the shell-like matrices can be renewed. When 
soft metal is used this style of mold with a cast iron frame gives the 
best results. 

Mold making by electrical deposition of metals is, on account of the 
plant required, possible only in the largest factories. For making 
a mold by this process a model is first made from wax or plaster 
of paris, with wire or iron supports. The model may thus be obtained 
in a single piece or in two pieces. It is next treated to an electro- 
lytic bath of copper sulphate, where it constitutes one of the elec- 
trodes and receives a coating of copper, the thickness of which depends 
on duration of immersion. The whole may then be coated with nickel 
to protect the surface and so that it can be polished. If the model is 
in a single piece a closed mold is formed; if in two parts the mold 
will open at one side and the edges of both parts will fit together accur- 
ately. Closed molds are cut into two portions by a saw. Molds 
obtained by electrolytic deposition are not very thick or strong. They 
are therefore backed by type metal or plaster. This is done by placing 
the mold in a shallow wooden box. The plaster of paris is run into this 
box until full. When molds are required for use under pressure they 
are reinforced by a thick electrolytic nickel deposit, and foundry metal 
is used for backing, instead of plaster. Electrolytic molds are easily 
and cheaply made but their use in rubber mills is questioned on account 
of their lack of sharp edges and ability to wear well. 



140 



R UBBEB MA rHIXEEY 




Fig. 131.— The Eggers Quick Cukixg Mold with Sclid Cast Irov Frame. 

Portland cement is sometimes used as a material lor mold mak- 
ing. It is placed in metal flasks and the desiretl shape formed. 
It is then coated with a layer of soluble glass (potassimn alumi- 
nimi silicate i and chalk, by which the details are worke<i np. Magnesia 
cement can be used, resulting in a very hard and durable mold. Such 
a mold presents smooth surfaces, sharp edges and gives good detail. 

The Eggees Qcick CrEi^'G Molds. 
The Eggers system of making soft metal mold castings for blown 
work is interesting. The walls of molds are often of unequal thick- 
ness. This causes loss of time in vulcanizing and cooling, extra work 
in handling, uneven vulcanization, etc. Fig. 131 shows one fonn of 
the Eggers mold designed to do away with this defect. The shells A are 
cast from soft metal such as tin. tvpe-metal. ahiminimi. etc. These 
shells are then placed in a female die of corresponding shape, into which 




Fig. 132. — The Eggers Quick Curixg Mold with Open Wrought Iron Frame.. 



MOLDS, METAL AND RUBBER 



141 



a male die is pressed. This swages the metal shell into final shape. The 
swaging removes all defects from the interior of the shell and gives the 
surface a smooth, glassy finish. The flanges B, hold the shells in posi- 
tion in the cast iron frames C. The two parts of the frame are held 
together by clamps D. 



The Eggees Opetst Frame Mold. 
Another form of the Eggers mold is shown in Eig. 132. In this 
the shells are also made of uniform thickness and are mounted in light 
iron frames. Referring to the drawing, the shells A are formed with 
flanges B. which fit into recesses in plates C. These plates are connected 
with the upper and lower frame plates D and E by screw bolts F, 
and the mold sections are clamped together by thumb screws G. The 




Fig. 133. 



Fig. 134. 



Typical Two- Part Molds. 



mold shells are cast from soft metal and finished smooth by swaging. 
In addition to the advantage of even vulcanization is the lightness of 
the outfit when a number of the molds are clamped together. The 
cost is less also, as this type weighs but one-fourth as much as the 
ordinary kind. 

Types of Metae Molds. 

Molds for motor tires are usually two-part, with a separate core 
inside. The rough castings are turned up on a lathe. If it is, for 
example, a ''Bailey tread," round depressions are milled in the inner 
surface of the mold. Eor this is used a milling apparatus on a flexible 
shaft, the depressions being accurately located by an indexing plate. 
Extreme accuracy characterizes every part of tire mold manufacture. 
A variation of more than 0.002 of an inch in the size of mold or core 
would mean its rejection. 



142 



RUBBER MACHINERY 



Fig. 133 shows a typical form of two-part mold with core for tires^ 
consisting of the core A and mold portions B and C. The illustra^ 
tion show^s a cross section of only one side of the mold. The tire is 
first built upon the core and placed in the mold, which is then subjected 
to pressure in a press-vulcanizer. 

Fig. 134 shows another form of tire mold of special design. In 
this the tread portion is formed with an interchangeable segment ring 
A with inclined faces to fit the faces on the mold parts 5 and C. When 
the mold parts are pressed together the ring A forces the tread of the 
tire radially against the core D, and holds the tire in place during 
vulcanization. 

Rubber articles, such as stoppers which have knobs or handles of 
irregular shape, often require molds of three or more parts. Fig. 135 
shows a luold for making waste plugs for baths, sinks, etc. The mold 




^ 



Fig. 135. — Type of Five-Part Mold. 



comprises ^ve parts, a lower plate A, a ring B, the upper plate C and a 
tw^o-part central block D. After vulcanization the parts of the mold are 
taken aw^ay one at a time to remove the completed plug, which is illus- 
trated at E. 



The Blaxd ]\roLDixG Machine. 

In Fig. 136 are two views of the Bland machine, which mechan- 
ically feeds the compound into the molds. In the illustration the 
machine is arranged to mold telephone receivers, although it may l)e used 
for making other articles by the substitution of the proper molds. The 
drawing on the left is a transverse section, while that on the risht is a 
longitudinal section. 

Beginning with the drawling on the left, the machine comprises a 
main casing A, having at the top a cylinder B with a piston 'J. At the 



MOLDS, METAL AND RUBBER 



143 



bottom is a cylinder D with a piston E. On one side is a cylinder F witli 
a piston G, and on the opposite side is a cylinder R with a piston I. Each 
of these pistons is reciprocated by steam pressure, which may be admit- 
ted at either end of the cylinder. Inside the casing are three mold sec- 
tions /. The central one is stationary and the two outside sections are 
dovetailed to the pistons G and I, so that the molds may be opened and 
closed. Above the molds is a stationary block K wuth twelve funnel- 
shaped feed tubes L which register with the molds. Between this block 
and the molds is a sliding plate M having holes which register with the 




Fig. 136. — The Bland Molding Machine. 



feed tubes. The plate is operated by a lever N attached to the piston rod 
of a small steam cylinder 0, so that the holes in the plate may be moved 
out of line with the feed tubes to stop the flow of compound into the 
molds. On the upper end of the piston rod P is a plate Q which car- 
ries the twelve cores R. On the lower end of the piston rod ^S* is a 
plate T, into which are threaded tamping rods U for packing the com- 
pound into the molds. 

Referring to the drawing on the right, the compound is fed into 
the hopper Fand forced by the screw TT' into the spaces X, from which 



144 



RUBBER MACHINERY 



it passes into the feed tubes L, the lower ends of which are closed 
by the plate M. The piston E is raised to bring the cores into the molds, 
which are then closed bv the moving pistons. The plate M is then 
moved to open the feed tubes, and the compound is forced into the molds 
and packed by the tamping rods U operated by the piston C. The 
molds are opened by moving the pistons outwardly, after which the 
molded articles, on the cores, are removed for vulcanization. 

Apparatus for Maki^sg Rubber Molds. 
A forming and vulcanizing apparatus for making elastic rubber 
molds or patterns for orna,mental objects, or for producing metallic 
articles by electro deposition, is illustrated in Fig. 137. J. is the 
vulcanizing vessel having a hinged cover B, supplied with bolts C for 
hermetically closing it. Within this vessel is a steam-chambered platen 
D supported on lugs E. This platen has inlet and outlet pipes F and G 




Apparatus for Making Rubber Molds. 



for supplying steam for heating it. A pipe H connected with the platen 
D is attached to an air pump (not shown.) The upper surface of the 
platen is provided with a number of holes / to furnish air communica- 
tion between the steam chamber and the inner surface of the mold. 
The pattern J is made of plaster paris or other porous material and its 
upper surface is shaped to produce the desired design. The mold is 
made from two thin sheets of rubber, one of which is partially vulcan- 
ized, while the other is unvulcanized. The combined sheet K is placed 
upon the pattern / with the partially vulcanized side up, and the edges 
of the sheet are cemented to the surface of the platen all around the 
pattern to exclude air from the under surface of the mold. The air is 
exhausted from the platen D by the air pump connected to the pipe H, 
and the suction through the porous pattern causes the rubber sheet to 
conform to its surface. Steam is then admitted at about 20 pounds 



MOLDS, METAL AND RUBBER 



145 



pressure to the vessel A tlirough pipes L, which causes additional pres- 
sure on the sheet of rubber and firmly depresses it into every cavity and 
outline of the pattern, and vulcanizes it. The completed mold will 
retain its shape and is easily stripped from castings of intricate design. 

Caee of Molds. 

To prevent the articles from sticking, molds are heated and 
brushed over with soft soap so that a film is deposited on the interior 
surface. Another method is dusting with French talc, plumbago or 
powdered soapstone, and in some cases a coat of glycerine is applied. 

Molds should be kept clean and when they gather scale from the 
sulphur, soap or talc, it should be removed. This fouling of molds is 
quite a serious matter and many preventives have been devised. One 
is to coat the inner surfaces with block tin, which can be removed by 
melting when foul. The sand blast is used for cleaning in some mills. 
A smooth talc sand, however, must be employed as a sharp silica sand 
would injure the surface. A circular wire brush mounted on a flexible 
shaft is also a quick and efficient tool for cleaning molds. 

Motor Deivex Mold Cleajn^er. 
Fig. 138 shows the Plank motor driven, flexible shaft outflt which 
is often used for cleaning: molds. The illustration shows the shaft with 




Fig. 138. — AIotor Driven Mold Cleaner. 

a circular wire brush. The flexible shaft is attached to the motor by 
a universal joint, which allows a wide range of movement of the brush. 
The shaft is usuallv from 6 to 8 feet lono;. 



146 



RUBBER MACHIXERY 





Fig. 139. — BeHt Driven Mold Cleaxer. 



Fig. 140. — Saxd-Blast Cleaner. 



Belt Dkivex Mold Cleaxee. 
Fig. 139 shows another form of flexible shaft driven from an over- 
head counter shaft. Mounted on the counter shaft is a large sheave 
pulley A over which runs a round belt B. This belt drives the grooved 
pulley C. The weight D, serves to maintain tension in the belt. The 
pulley C drives the flexible shaft E, on the end of which is mounted a 
circular wire brush F. 



Saxd-Blast Cleaxee. 
One type of sand-blast for use in cleaning molds, is illustrated in 
Fig. 1-10. The device comprises an outer casing .1 having an air-inlet 
pipe B and an outlet C, to which rubber hose D is attached. The outlet 
pipe C receives sand from a hopper E supported inside the casing. 
Sand is fed into this hopper through a valve F which is opened and 
closed by a disk G on the rod H. This rod is controlled from the out- 
side by the lever /. On the lower end of the rod H is a ]dunger J , 
which clears the outlet pipe in case it becomes clogged. The flow of 
sand from the hopper E is controlled by a sliding valve K operated by 
the lever L. 



MOLDS', METAL AXD RUBBER 147 

Machixe Tools foe Mold Makixg. 

]\IaiiT rubber mills have a mold making department that is in 
reality a completely equipped machine shop. The machine tools that 
are required in such a shop are : 

An 18-inch engine lathe with a three-step cone and double back 
gear. It has an 8-foot bed and takes 2 feet 6 inches between centers. 

A 21:-inch planer with an 8 foot bed and one or two heads. 

A shaper with a 20-inch stroke and a table travel of 22 by 14% 
inches. It has a universal vise that opens 10% inches. 

A plain milling machine back geared with a table feed of 24 by 19 
inches and a cross feed of 7 inches. Universal index centers for gear 
and worm cutting, spiral milling, etc., are also necessary. 

A 20-inch drill press with power feed and tapping attachment. 
The diameter of the table is 16% inches. 

A 13-inch sensitive drill with a capacity up to a %-inch hole 
and a spindle feed of 4% inches. 

A 13-inch speed lathe with a set-over swivel tail stock and a 
distance of 48 inches between centers. 

A universal tool grinder for grinding reamers, cutters and other 
tools. This can also be used for surface grinding. 

An emery wheel bench grinder and grindstone. 

A swing frame grinder that consists of an emery wheel mounted 
on a flexible shaft. 

Tor soft metal molds, a 23 x 34-inch brass furnace with drop 
grate is required as well as an equipment of iron bowls, ladle and 
crucible tongs. 



CHAPTER IX. 

VULCAXIZEES— GEXEKAL TYPES. 

I!X curing or vulcanizing there are trvo processes, the hot and the 
cold. In the first the application of heat is as follows : open steam 
heat, hot air or dry heat, hot water, electric heat, hot melted. 
sulphur, solar heat and Ultra-Violet rays. The cold cui"e consists of 
two methods, the immersion of imcured rubber in a bath of chloride 
of stilphiu', or the exposure to chloride of sulphur fimies. The appara- 
tus for applying the cure is infinitely varied. Eor the open steam 
heat there are horizontal vulcanizers and vertical kettles : for dry heat, 
jacketed vulcanizers: for the "acid" or cold cure, immersion tanks: 
for the vapor cure, vapor chambers ; for the solar cure, simning tables ; 
for sulphur baths, heated tanks. All of these general divisions have 
scores of types of appliances for the vulcanization of special goods. 




Fig. 141. — Hoeizoxtal A ulcaxizes.. 

The manufacturer does not know exactly what chemical changes 
occiu' during vulcanization. Xor does the baker know what happens 
chemically when he bakes bread. Experience enables the bread baker 
and the rubber baker to produce goods in great quantities that are in 
every way acceptable. It is probable that for years to come ofi'-hand 
tests for vulcanization will be made by denting with a horny thumb 
nail or by observing the slowly fading tooth marks made by biting a 
sample imder test. 



VULCANIZERS— GENERAL TYPES 



149 



The method of vulcanization most commonly employed is the 
open steam cure. What is known as a vulcanizer or heater is used. It 
is built like a horizontal boiler shell with a door at one end (sometimes 
at both ends). In this the goods to be vulcanized are loaded. They 
are wrapped in cloth, buried in talc or soapstone, or confined in molds 
to preserve their shape as they soften before vulcanizing begins. The 
door is then closed and live steam turned in and kept at the proper 
temperature until vulcanization is effected. While vulcanizers were 
formerly made by almost any boiler maker, they are today usually 
furnished by manufacturers of rubber machinery. The standard sizes 
run from 12 to 84 inches in diameter, and of any length required. 

Horizontal Vulcajn^izee. 
The simplest form of live steam vulcanizer is shown in Fig. 141. 
A is the shell; B, the steam inlet; C, steam outlet; D, door flange; 
Ej swinging bolts, and H, the door. The carriage track F is set in 
grooved stands riveted to the shell, and moves with the car G when 
loading and unloading. 

Vertical Vulcanizer. 
Fig. 142 shows the ordinary vertical or kettle vulcanizer, which 
is also of the live steam type. It is a heavy iron pot provided with 




142. — Vertical Vulcanizer, 



a bolted-on head. It has the usual steam gage, inlet and outlet con- 
nections and drain pipe. This vulcanizer is so simple in construction 
that the illustration explains itself. 



150 



RUBBER MACHINERY 



Horizontal Jacketed Vulcaxizee. 
Fig. 143 shows a horizontal, jacketed vulcanizer, having an outer 
wall A, and an inner wall B. Between these walls is a space C, which 
serves as a heat insulator when the open cure is used in the chamber D. 
In the dry heat process steam is introduced into the space C through 
the inlet E, in which case the main inlet F is closed. Pressure valves 
G and H are provided in the inner and outer walls, while drain cocks 
K and L allow condensation to be drained off. The goods to be vul- 
canized are placed on a long car M and run into the heater on the 
track P from an outside track N. The door Q is then closed and 
fastened by the bolts Pi, and steam is turned on. 




Fig. 143. — -Horizontal Jacketed Vulcanizer. 

Dry heat in ordinary practice means air heated by steam con- 
fined in pipes or in jackets adjacent to the air. In the olden time it 
was, however, customary to have the dry heaters set above coal or 
wood furnaces, the heating being done by the flame on the outside. 



Vertical Dry-Heat Yulcajn^izer. 
In Fig. 144 is shown a vertical, jacketed dry heat vulcanizer. It 
has two shells A and B and is supported in a pit C by the flanges D. 
The hinged cover has eye bolts E and is clamped in place by swinging 
bolts. In the cover is a tube F, closed at its lower end, in which a 
thermometer is inserted to record the temperature of the interior. 



YULCANIZERS— GENERAL TYPES 



151 



Dry heaters, which are really oven rooms twenty to thirty feet 
long and eight to ten feet high, are also used in certain lines of 
manufacture, such as shoes and clothing. In them the principle is 




Fig. 144. — -Vertical Dry Heat Vulcanizer. 

the same as in the smaller dry heaters just described. The newer 
types of dry heaters where air under pressure is used are described 
in Footwear, as is also the so-called vacuum cure. 

The Seabuey Vulcaa^izer. 
Seabury's hot-jacketed vulcanizer, illustrated in Fig. 145, is of 
the horizontal type, having a heating jacket to assist in keeping the 
steam at a high temperature and prevent it from condensing on the 
walls. The goods are placed in A, surrounded by B, which leads 
directly from the fire box C, so that the flames and hot gases surround 
the vulcanizer and pass up through the flues D into the chimney E. 
Steam is admitted through the perforated pipe F which runs along the 
bottom of the vulcanizer. The usual fittings are a blow-off valve C, 
gage K and thermometer L. The door H is mounted on a roller so 
that it is easily moved. 



152 



RUBBER MACHINERY 



Fkench Vertical Vulca^^zer. 

Fig. 146 shows a French type of vertical vulcanizer in which the 

door is provided with a counterweight. When closed, the door is 

clamped to the cylinder by bolts A, hinged at B so that they can be 

swung quickly into the slots in the flanges. The counterweight C 




Fig. 145. — The Seabury Vulcanizer. 

is adjusted to balance the door, for ease in opening and closing. The 
vulcanizer has a steam inlet D, drain cock E, gage F, thermometer 
G and connection H for a pressure relief valve. 

The Fowler Steam Separator ais^d Vulcai^izer. 

The Fowler apparatus, Fig. 147, is designed for uniform vul- 
canization and to prevent the formation of blisters. 

When water is evaporated, gases such as oxygen, nitrogen, car- 
bonic acid and ammonia are freed and pass into the vulcanizer with 
the steam, where they remain as fixed gases and do not condense. 
Fowler's process is intended to remove these gases from the water 
before it is used to produce steam for vulcanization. This is done 
by heating the water, then cooling it, and removing the freed gases. 

The water is sprayed from a supply main A into a closed tank B. 
Here the water and its gases are separated, the gases being drawn off 



VULCANIZERS—GEXERAL TYPES 



153 




Fig. 146. — French Vertical Vulcanizer. 

througli the pipe C by piunp D. The water runs oif through a pipe E 
into a supply tank F^ from which it is forced by the pump G into the 
boiler H, arriving there free from gases. V is the vulcanizing tank, 
having a pipe I connected with the boiler for the admission of steam. 
Through the pipes K and L, the air can be exhausted from the vulcan- 
izer by the air pump D. 




J_i_. * A ■ < 



£ 



^^S 




Fig. 147. — The Fowler Stea:m Separator and Vulcanizer. 



154 



RUBBER MACHIXERY 



The AYittexbeeg Vulca^^izee. 

Fig. 148 is an apparatus in which the heat and pressure in the 
heaters is varied independently of each other. The low pressure chamber 
is for porous goods, while dense effects are secured in the high pressure 
chamber. 

A and B are two vulcanizers heated by closed steam pipes C and D 
and connected by pipe H, which has cut-oif valve I. Pipe G connects 
B with the suction side of the pump E and has a cut-otf valve >S'. Pipe 




Fig. 148. — The Wittenberg Vulcaxizer. 



F connects A with the pressure side of the pump and has a cut-off 
valve R. Valves J , K, L and J/ are air vent valves. Different pres- 
sures are obtained in the heaters A and B by operating the pump and 
opening and closing the proper valves. 

CoxTixrors Peocesses. 
The usual vulcanization of rubber goods is of necessity intermit- 
tent. It consists of placing shaped articles in some sort of mold, shut- 




YiG. 149.— The Eddy Coxtixuous Vulcaxizer. 



VULCANIZERS— GENERAL TYPES 



155 



ting the mold in a viilcanizer or press, where it is left for minutes 
or hours, then taken out and opened. It has, however, long been the 
dream of manufacturers to have some sort of continuous process of 
vulcanizino' where the goods pass from the making-up room directly 
into a vulcanizing mechanism, through it and on to the finishing 
department without interruption. This has been done in spreader 
work and in hose. 



The Eddy Peocess. 
Fig. 149 shows a continuous process vulcanizer for curing small 
goods. The vulcanizing chamber .1 contains steam coils B and a damper 
C at the top. A pair of endless chains D are connected bv cross-bars with 
a number of perforated trays E hanging from them. The chains are 
driven by large sprocket wheels G and pass into the chamber A and 
around the three sprocket wheels F. Power is applied to the belt 
pulley H and the chains are driven as such slow speed that the goods 
in the trays are cured while passing through. The operator fills and 
empties the trays at the front of the sprocket wheels G while the 
machine is in motion. 

Cold Cure Appaeatus. 
To show how proofed cloth is cured by a chloride of sulphur 
solution. Fig. 150 is added here. The roll of proofed cloth is placed 




Fig. 150. — Cold Cure Apparatus. 

in the machine at A. The fabric passes around the guide roller B 
and over rollers C C immersed in the vulcanizing solution E E in the 
lead lined troughs D D. By depressing the guide F the fabric is 
brought in contact with the vulcanizing solution. The treated fabric 
then passes over the guide roller G and around the heated drum H, 



156 



RUBBER MACHINERY 



to hasten the evaporation of the solvent. After passing around the 
last guide roller I the cured fabric is wound up on the roller /. 

The vapor cure is done in a great variety of dry heaters, large 
and small. A point of difference betvv^een the steam dry heater and 
the vapor cure chamber is the necessity for exhaust appliances in the 
latter, that the irritating fumes of the sulphur chloride may not injure 
the workmen. 

The sun cure, or solarization, is not used on any considerable 
scale today. Twenty-five years ago, when ^'Gossamer" rubber coats 
were very generally worn, the sun cure was universal. The apparatus 
consisted of tables placed out of doors so that the rays of the sun fell 




French Hot Air Vulcanizer. 



directly upon the rubbered surface. If the sky was clear the cure 
was excellent. Vulcanization by dry heat, however, proved so much 
more reliable that in time solarization ceased to be employed. 



Feench Hot Air Vulcanizee. 
Fig. 151 shows a French type of hot air vulcanizer. 



The steel 



tank A is closed at One end and has a hinged door B at the other. 
Inside the tank is a steam coil C and at each end is a small electric 
motor D, driving a fan E on the inside to stir up the air and main- 
tain an even temperature in the tank. A steam jacket may be sub- 
stituted in place of the coils, and the fans operated by belts. 

Kepaie Yulcanizees. 

In the line of general vulcanizing comes the repair of small rubber 

goods. In tire repair the small vulcanizers are infinite in number and 

variety. For small general repair and experiment they are few. The 

apparatus shown in Fig. 152 is designed for use by dealers in rubber 



YULCANIZER8— GENERAL TYPES 



157 




Fig. 152. — Repair Vulcanizer. 



goods in repairing siicli small articles as hot water bottles, air bags, 
etc. The apparatus consists of a table A placed above a steam genera- 
tor B which is heated by gas through the tube C. The generator is 
fitted with a gage D which regulates the gas supply so that the required 
steam pressure may be maintained for any length of time. The article 
to be vulcanized is placed between the table A and the plate E, the 
pressure being regulated by the weighted lever F. 




Fig. 153. — Electric Vulcanizer and Tire Mold. 



158 



RUBBER MACHIXERY 



The Riddle Electric Vulcaxizers. 

Xumbers of viilcaiiizers heated by electricity have l^eeii invented 
in the ^oast but so far they are used chiefly in tire repair. The Riddle 
vulcanizer utilizes electricitv both for heatina: the molds and holding 
them together in the place of the usual clamp. The principle of this 
invention was applied to a number of different forms of vulcanizers. 
three of which are illustrated and described herewith. 

Referring to Fig. 153, A and B are two halves of a tire mold in 
which the tire C is placed with an annular key or ring D projecting 
through it at the base. Inside the tire is an inner tube E which is 
inflated to hold the walls of the tire against the mold. Inside the tube 
E is an annular electric coil F, which supplies heat for vulcanization. 
The ends of the coil pass out through the tire valve opening C to the 
source of current. 




Fig. 154. 

Fig. 15^ shows an application of two electric coils in which one 
coil is used for heating and another for clamping the molds together. 
At H are shown the coils for heating the tire B. C is a solenoid or 
electro-magnet, Avhich draws the plates I of the toggle joints together, 
forcing the levers -/ downward and clamping the mold together. In 
place of the heating coils, magiio-thermal coils may be used both for 
clamping the molds together and for supplying heat. 




Fig. 155. 



Fig. 155 shows the application of both heating and mafl^letizing 
coils to the horizontal type of vulcanizer. Between the shell A and 



rULCAyiZERS—GEXERAL TYPES 



159 



the lining 5 is a heating coil C connected with the source of current 
by the terminals D. The magnet coils E and F are placed in grooves 
in the door G and shell ring A, and when energized they hold the door 
tightly closed. 

SuLPHUE Bath. 
The sulphur bath for vulcanizing pure gum goods is a very simple 
contrivance. It is an iron vessel, lead lined, arranged so that it may 
be heated enough to melt the sulphur. It is also fitted with an exhaust 
hood to carry away and deposit the sulphur fumes. By keeping the 
sulphur molten and by occasionally removing the scum, continuous 
process vulcanization may be carried on as there is no opening or 
closing of heater doors. The goods after the cure must be treated 
with soda solution to remove the surface sulphur. 





Fig. 156. — The Adamson Self Sealing Door. 

Other special vulcanizers will be found in the various chapters 
devoted to their own lines of work. 



YuLCAXizER Doges. 
Quick-closing devices for vulcanizer doors have come into vogue 
very generally in the past few years. The idea is not new, however. 
Dental vulcanizers by the score were long ago fitted with quick closing 
and opening devices. To an extent also in English, German and 
American factories, vulcanizers were fitted with variations of the sim- 
ple hinged bolts. There were the bayonet lock idea, the wedge door, 
etc., etc. Ten vears aao the veteran rubber manufacturer, Franz 



160 



RUBBER MACHINERY 




Fig. 157. — The Williams Quick-Lockixg Door. 

Cloiitli, patented a system of bolts that fastened by wedge faces instead 
of screw threads. Some of the later and generally accepted forms of 
quick-closing doors are described below. 

The Adamsox Self-Sealixg Dooii. 
In the Adamson vulcanizer. Fig. 156, A is the shell and B the 
head. Extending from the lower half of the flange C is a lip D with 
a concentric groove E, into which the lower half of the door fits. On 
the upper half of the door is a similar lip F with a concentric groove 
G which fits into the upper half of the flange C. In the face of the 
flange C is an annular groove H containing a packing ring I. Through 
the opening J, steam or water under pressure is forced into the groove 
behind the packing. To close the vulcanizer the door is lowered into 
the grooves E and G and the steam or water pressure turned on behind 
the packing ring. 

The Wileia^is Qeick-Lockixg Door. 
Another quick closing and locking door is shown in Tig. 157. In 
this case the door A and shell B have flanges similar to those in which 
bolts are used, but the door is held to the shell by a pair of grooved 
semi-circular rings C which fit over the flanges when the door is closed. 
The rings C are hinged to the top of the door and have rollers D which 



YULCANIZER8— GENERAL TYPES 



IGl 



run oil the vertical guides E when the door is lifted, thus forcing the 
rings outward and away from the flanges. The door and grooved 
rings are supported by cables F and G attached at their upper ends 
to the ring H. The cables F are shorter than G so that the rings C 
will be pulled outward away from the door, which is then lifted by 
cable G. To lock the door, it is lowered in front of the heater ; the 
rings C join at the bottom and the lower ends are locked by a lever I. 
To seal the door, steam or water pressure is forced behind the packing 
ring J through the pipe K. 

Hydeaulic Door Closii^g Device. 
In Fig. 158 is shown a German type of horizontal vulcanizer in 
which the door is hydraulically sealed. The head A and door 5 are 




mr~^ 




Fig. 158. — Hydraulic Door Closing Device. 



planed off and fitted with a packing joint. The door is suspended 
by a cable C which passes over pulleys D and bears a counterweight E. 
The door is cast with projections F having slots which fit over the 
ends of the rods G when the door is in place. On top of the vul- 
canizer is a hydraulic cylinder H, the piston / of which bears a cross 
yoke /. This yoke is connected with levers K pivoted to the sides of 
the vulcanizer at L and operate the vertical yokes M. To close the 
door it is lowered so that the slots in the arms F fit over the ends of 
the rods G. Then water is admitted to the cylinder //, raising the 
yoke / and the levers K, and forcing back the yokes M and rods G. 
This forces the door tightly against the end of the heater. 



162 



BUBBER M AC my E BY 




F^M 



Fig. 159. — The Shaw Door Lock. 



)^^^^K^I^^^^ 


J 


! 



Fig. 160. — The Bridge "AKROx-WiLLiAiEs" Door. 



VULGANIZERS— GENERAL TYPES 163 

The Shaw Door Lock. 
Anotlier type of quick-locking cloor, designed by Shaw, is shown 
in Fig. 159. The drawing on the left shows the door in place, while 
on the right is a section throngh the center of the door and body. On 
the outer end of the shell C is a heavy ring D with a groove containing 
a packing ring E. The ring D supports eight thrust blocks F having 
wedge-shaped lugs G which are adjustable longitudinally by set-screws 
H. Riveted to the outside of the door I is a heavy ring / having a 
bearing upon which revolves the latch ring K. This has eight wedge- 
shaped blocks L, which engage the lugs G when the ring is turned by 




Fig. 161. — The Williams Boltless Head. 

the locking lever M. The hinges N are attached to the door by adjust- 
able bolts Oj which allows the hinge connection to be made without 
binding after locking the door. 

The Beidge ''Akeox-Williams'' Dooe. 
Fig. 160 illustrates a quick-closing door, which is raised and 
lowered by a rack and pinion movement operated by a pair of hand 
wheels. The door or "head" is count erweighted and slides in machined 
guides. The shell ring, against which it fits, has a circular groove 
containing a U-shaped packing ring with a wedge-shaped extension. 
Steam, air or water under pressure is admitted behind this packing, 
and forces it ao-ainst the door, sealing the vulcanizer. When steam is 



164 



RUBBER 2IACHINERY 



turned into the vulcanizer it presses the wedge extension of the pack- 
ing ring against the inner face of the door, thus effecting a double seal. 

The \Yilliams Boltless Head. 
This head, adapted to be attached to the bolted-on door to convert 
it to the quick closing type, is illustrated in Fig. 161. The shell 
ring to which the door is hinged is bolted to the old shell ring. The 
door rotates on a trunion at its center, supported by an adjustable 
bracket hinge. The shell ring and door have a series of projecting 
lugs and a wedged-shape packing ring. The door is turned by an iron 
bar forcing the door lugs under those of the shell ring. This locks 
the door and the internal steam pressure acting on the packing seals 
the joint. 

The Aleex Dooe. 
A quick opening door that can be fitted to any vulcanizer door 
frame is shown in Fig. 162. It swings on a vertical axis, suspended 




Fig. 162. — The Allex Door. 



between two ball bearing arms which are hinged to the head flange. 
The door thus closes squarely against the packing. It is locked on the 
inside by three grooved segment rings, pivoted at one end and moved 
by tangent bolts attached to the free ends. The bolts are operated 
from the outside by turning a short shaft which projects through the 
center of the door. 



CHAPTER X. 

VULCA:\TIZI]SrG peesses, sceew axd hydeaulic. 

TTIHE simplest form of vulcanizing press is the small single screw 

I press with one opening for molds, from six inches square and 

upward, with the upper and lower plates chambered for steam. 

This press is used for curing everything in the way of small mold 

work. 




Fig. 163. — Knock Press. 



This press is shown in Fig. 163. The two platens A and B 
are cored for steam and made sufficiently strong to withstand a 
pressure of 100 pounds per square inch. They are usually 12 to 15 



166 



RUBBER MACHINERY 



inches square. The upper platen is suspended from the screw C, 
which is threaded through the upper part of the frame. The hand 
wheel is made heavy and has a clutch in the hub, enabling the operator 
to apply a series of hammer blows to the screw. For this reason it 
is known as the ''Knock Press." 



Small Standard Press. 
The common form of 20 x 20-inch screw press has the following 
principal features: A lower steam platen which has a finished upper 
surface is supported by a frame or table. This platen supports four 
heavy bolts that carry the head and are rigidly attached to it. The 
upper movable steam platen has a finished under-surf ace and is attached 
to the lower end of the screw. This platen has offsets at the cor- 
ners which act as guides. The screw passes through a threaded 
nut in the center of the head and is provided with a hand wheel at 
the top, by which the press is opened and closed. 




Fig. 1o4. — Double Screw Press. 



VULCANIZING PRESSES 



167 



Double Screw Press. 
As a rule, screw presses are of small size, but by using two or 
more screws working through worm gears, large platens may be 
employed and considerable pressure exerted. The press shown in 
Fig. 164 is a German type in which high pressure is obtained by 
worm gears. Referring to the drawing, the lower platen A is sta- 
tionary, while the upper platen B slides on the four columns C, and 
is raised and lowered by the worm gears D, which are turned by the 
hand wheels E. The worm gears turn the internally threaded nuts Fj 
which fit the vertical screws G at the upper ends of the columns C. By 
this means the upper platen is raised and lowered. The platens are 
chambered for steam, with inlets H, outlets I and pressure gages K. 

Toggle Joint Press. 
Toggle joint presses are made in sizes from 12 x 14 to 66 x 72 
inches. This type of press is shown in Fig. 165. It has three steam 




Fig. 165. — Toggle Joint Press. 

platens A, B and C, the center one being suspended from the frame 
by adjustable bolts. The lower platen rests on a heavy base plate 
supported by four columns. The upper platen is raised and lowered 
by a pair of toggle joints operated by right and left-hand screws D and 



168 



RUBBER MACHINERY 



Ej and a pair of hand wheels F and G. The press has an indicator 
H, which shows the amount of pressure exerted on the molds between 
the platens. 

Hydraulic Presses. 
Hydraulic presses are made in standard sizes. Square presses 
with single rams are manufactured in the following sizes : 12, 18, 
24, 30, 36, 40, 48, 52, 60 and 72-inch. A standard 3(5 x 36-inch 
square hydraulic press has one 12-inch ram which fits in a vertical 
cast iron cylinder having a base which supports the four steel columns. 
The top of the cylinder is counterbored to take a U-shaped packing 
and has a removable packing flange bored to the size of the ram and 
attached to the cylinder by bolts. The ram has a flange, which is 
bolted to the follower plate or lower steam platen. This platen is 
36 inches square, five inches thick, and is chamlpered for steam. It is 
cast iron, with a smooth finish on the upper side, and has bearings for 
the columns to guide the platen as it is moved up and down by the 
ram. The top platen is fastened to the four steel columns which 
support it. It is finished on the under side, chambered for steam 
and has the same construction and dimensions as the lower platen. 
Both the top and follower platens have steam connections, and the 
cylinder has a hydraulic pipe connection and valve. 




Fig. 166. — The Swan-Neck Press. 



VULCANIZING PRESSES 



169 



Single ram hydraulic vulcanizing presses are built with additional 
steam platens faced off top and bottom to form several vulcanizing 
spaces. These are termed multiple presses. In these the columns 




Fig. 167. — Adamson Single Ram Press. 

are made longer and the additional steam plates are held at fixed dis- 
tances apart when the ram is lowered. 

The Swaist-J^eck Peess. 
Fig. 166 shows a simple form of a small hydraulic press. The 
ram operates in the cylinder A which is cast integral with the frame B. 
On the head C of the ram is attached one of the steam platens D, 
while the upper platen E is attached to the frame. Steam is applied 
through the pipe F, and exhausts through pipes G and the trap H. 
Water for operating the ram is supplied to the cylinder at /. 

Three Platen Press. 
This type is shown in Fig. 168. It has an adjustable platen B 
interposed between the platens A and C, which are supplied with steam 



170 



BVBBEE MAC RISE BY 




^'A 






-^ e±^ 



Oj/ pi. \^ 




Fig. 168.- 



-Thsee-Platex Przss. 



tkroTigh the inlet pipe -D. At tiie opposite side of tJie platens tlie 
steam exhausts through i-he pipe E. The pipes E and G snpplv steam 
to platens B and C . and have sTring joints which allow them to be 
moved vertically. The heavy construction of the frame, pin Tiger and 
bolts for the head, is typical of this type of press where very high 
pressures are obtained. 

The Ga^'Ct Peess. 
For vulcanizing long articles, such as rubber matting, sheet pack- 
ings belts and similar products, the gang press with continuous heating 
platens is used. In Tigs. 170 and 171 the four separate hydraulic 
cylinders A are operated simultaneously from the single water line B. 
Attached to the heads of the plungers C, is a continuous platen E, 
which has a steam inlet and outlet at B. The upper heating platen E 
is also continuous and has a steam inlet and otitlet at G. Ta order to 
move the article to be vulcanized in and out of the press, a tiaveling 
table El is employed. Extending along each side of this table is a 
toothed rack which engages a pair of gears / operated by the crank 
-ST. As the table is moved outward, it rests upon rollers J placed above 
the table Z. 



VULCANIZING PRESSES 



171 



The Adamso^ Yulcanizer Press. 
Fig. 1Y3 illustrates a viilcanizer press in which the shell ^ is a 
steam chamber and also a support for the head. It consists of a lower 
flange F^ a shell E and an upper flange R, which support the head I. 
The flange and head have lugs H and J which lock the head in place 
when it is given a turn. The joint is made steam tight by an expand- 
ing packing ring K. The uprights L support the head when raised 
and the chamber E is drained by the pipe G. The ram A operates in 
the cylinder B which has hydraulic connections at C, The upper end 
of the ram has a platen D that supports the molds. To operate the 
press, the ram is raised, lifting the cover, which then rests on the 
supports L. The ram is lowered as the molds are placed upon the 
platen, until the chamber is filled. The head is locked in place and live 
steam is turned on at M. The hydraulic cylinder is suspended in a well 
N and the press-vulcanizer rests on the floor. 

The Fillii^gham Vulcaistizee Peess. 
In the hydraulic press shown in Fig. 174 the head is forced 
down against the molds, while the platen which supports them is moved 




Fig. 169. — The Farrel Two-Ram Press. 



172 



RUBBER MACHIXERY 



independently of the head and the steam chamber. It consists of a 
hollow stationary column C bolted to a heavy bed plate. The stationary 
ram D is attached to C. The cylinder E has stuffing boxes at each 
end and reciprocates on C and D by hydraulic pressure applied at 
F or X acting' on the head D. The bolts S are attached to E and their 




Fig. 170. — The Gaxg Prp:ss. 



f KOCOOO 




Fig. 171. — Exd View of Gaxg Press. 




Fig. 172. — Berstorff's Sevex-Platex Press. 



VULCANIZING PRESSES 



173 



upper ends engage slots in the cover P. These slots open into holes 
through which the bolt heads pass when the cover is raised. 

The steam jacketed chamber A has an upper flange L through 
which the bolts S pass. It moves vertically over the column C. On 
the upper end of this column rests a platen H which supports the 
molds I. It is attached to the upper end of a ram / which reciprocates 
in C. 




L 



M 



N 



■V 



M 



■B 



\F 



'6 



\a 







illILK^/- 








i 

1 


B^P ^ 




c- 


-J 


mrn^. 


WmwM 









Fig. 173. — Adam son Vulcanizer Press 



Fig. 174. — The Fillingham Press. 



To operate, the cover P is turned by the hand wheel which 
disengages the lugs 21/ and clears the bolt heads so that the cover is 



174 



RUBBER MAC HIS FRY 



raised and suspended by liook Y. Water nnder pressure is admitted 
at G, below D, forcing down E wbicli lowers the chamber A nntil the 
platen // is exposed at the top. The molds are then placed upon it 
and water admitted at F, above D , which forces up E and raises the 




Fig. 175. — English \'ulcaxizer Press. 

chamber A. The cover is then locked in place and the space between 
the molds and cover is taken up by operating the ram J. The do^vn- 
ward pressure is then applied and steam admitted to the heater or 
jacket as desired. 



VULCAXIZIXG PRESSES 



175 



The Shaw Hoeizoxtal Vulcaxizee Peess. 
Another type of liYclraulic press viilcanizer is shown in Fig. 176. 
It is used for curing solid tires made in straight lengths of abont 15 
feet. It mav be used, however, for vnlcanizing any kind of rubber 




'ijL^i ^^ t|^ ijL^ (iL^ h^ i]|L^ 
Fig. 176.— The Shaw Horizontal \'ulcanizer Press. 




Fig. 177. — The Perrin Hixge Table Press. 



176 



EUBBER MACHIXERY 



goods that require long molds. It comprises a horizontal shell A, 
seven hydraulic rams B, six long molds C and power driven rollers 
for conveying the molds into the cylinder. The rams are all operated 
from a common water line so that they work in unison. The molds C 
are lifted on a car D (only part of which is shown) and moved to the 
front of the heater, and the shafts E and F are coupled by the jaw- 
clutch H. The bevel gears G drive a series of horizontal rollers J, so 
that when the shafts are rotated by the belt pulley I, the molds are run 
into the press. The molds, which are separated to allow circulation 
of steam around them, are then subjected to heavy pressure by the 
hydraulic rams, after which steam is admitted through inlet pipes K. 
After vulcanization the shafts E and F are reversed and the molds 
run out. 

Hydraulic Accumulators. 
It is common practice to have in the hydraulic system an accumu- 
lator for storing water pressure. It regulates the action of the pump 




FiG. 178. — The Thropp Swing Table Press. 



VULCANIZING PRESSES 



177 



and keeps the water pressure constant. It is more economical to 
employ a small pump working under a uniform pressure all the 
time than a large pump part of the time. For low pressure, a 
tank placed at a certain height above the work will give sufficient 
pressure. But to supply high pressures by gravity only would require 
a tank a quarter of a mile high, and for this reason the accumulator is 
employed. 

It is a vertical cvlinder closed at one end and havino; a ram work- 



ing throuo'h a stuffina; box. 



The ram carries a load of iron weights 



T-f 





Fig. 179. 



Accumulators. 



Fig. 180. 



on a platform suspended from its head. Sometimes a tanl^ is employed, 
into which slag, stones, brick, etc., are thrown to make up the required 
weight. The accumulator should be placed as near the pump as 
possible. The intensifier is a modified form of accumulator. It con- 
sists of a piston operating in a cylinder, the piston rod passing through 
a stuffing box in the top of the cylinder, and working in a second 
smaller cylinder above the main cylinder. Water enters the larger 
cylinder and forces up the piston working upon the upper small piston. 



178 



BUBBER M AC HI X FRY 



The intensilied pressure is delivered from the small cylinder. The 
ratio of areas of the two pistons gives the degree of increase of pres- 
sure produced. 

Fig. 179 shows an accumulator with a tank A for containing 
weights. When the plunger B reaches its maximiun height, the edge 
of the tank. A lifts the lever C^ and by the chain D the lever E is also 
raised. This closes the valve F and stops the pump until the amount 
of water in the accumulator is reduced by use. when the pump starts 
again. 

Fig. ISO shows another form of accumulator, in which .4 is the 
cylinder. B the phmger and C the crosshead from which a platform D 
is suspended by four bolts E. Upon this platform are placed the 
required number of iron weights. When the plunger reaches a cer- 
tain height the crosshead strikes against a stop attached to a chain and 
closes a valve placed in the line between the pump and the accumulator. 
This stops the pump until the amount of water in the accumulator is 
reduced sufficiently to allow the valve to open. 




iiiiiiiP'^ 





Fig. 181.— Farrel Multiple Ram Belt Press. 



CHAPTER XI. 

TUBE MAKING MACHINERY. 

RUBBER tubing for mam' years was made wholly by hand. It 
ran in length from 18 inches up to 15 feet. The hand pro- 
cess was as follows: 

The stock for the tubing was calendered quite thin on cotton 
sheeting, which, as fast as spread, was wound upon a wooden shell. 
The table upon which the tubing was made was zinc covered and very 
smooth and level. The roll of sheet rubber hung in a rack consisting 
of two uprights, with bearings for a horizontal bar running through 
the shells. The foreman of the tube makers with a clean, square 
stick, a trifle longer than the width of the sheet, drew a sheet of rub- 
ber off the roll upon the table while one of his assistants wound the 
cotton sheeting off upon the second shell. The sheet of rubber was cut 
off the roll, leaving it a little more than 15 feet in length. The tube- 
makers then gathered in their places, all on the same side of the table,, 
the cutter standing farthest from the roll. The further edge of the- 
rubber sheet was secured to the table to prevent slipping. 

The mandrels or wires, which formed the cores of the tubes, were 
laid upon a table at the back of the workers. They were previously 
treated to a coating of soft soap, and dried, after which a light coating 
of cement made of mixed sheet and naphtha was brushed over them. A 
wire was laid upon the edge of the sheet, which had previously been 
trimmed by the cutter. The four tube makers struck it gently to stick 
it to the sheet. It was then raised free from the table and the sheet 
rolled around it three or four times, gages in the hands of the v\'orkers 
determining its size. The cutter then, wetting his blade, went to the 
further end of the table and walking backwards, by a single long sweep- 
ing stroke cut the tube free from the sheet. After being rolled for- 
ward and back several times, and possible blisters pricked, the tube 
was deposited upon the rear table, which was upholstered with a mat- 
tress of cotton cloth to prevent the unvulcanized rubber from flattening. 
The same process was repeated until the entire sheet was used. 

Then came the wrapping of the tubes in cloth. Long strips of 
cambric, muslin or other fine cloth were wet and laid upon the rear 



180 RUBBER MACHINERY 

table. The end men, taking the top strip, lifted it ovex and stretched 
it upon the zinc table. A tube was then laid upon the cloth, the edge 
lapped over it, brushed dow^i with the fingers, drawn tight, and with 
a quick roll wrapped securely. The wrapper was further tightened 
by rolling, either with four short boards, or with one long, fifteen- 
foot board. An iron pan, upon which was laid a thin mattress of 
coarse cloth, received the tubes for the vulcanizer. They were packed 
in layers, three — sometimes four — deep, depending upon the size of 
the tube and the weight of the mandrel. 

This process was so slow that it was soon superseded by the 
mechanism known as the tubing or spewing machine. Briefly described, 
this consists of a horizontal cylinder, jacketed to hold steam. Fitting 
this cylinder is a powerful worm or archimedean screw, and at one 
end of the cylinder is an opening into which the rubber is fed. At 
the other end is a die through which the screw forces the plastic rubber. 

The principle upon which the first rubber tubing machine was 
constructed is still followed. The application, however, is so much bet- 
ter understood and so many changes have been made that the latest 
tubing machines so far excel them in productive capacity and general 
usefulness that the change from the old machine to the new is of more 
economic importance than the first radical change from hand work to 
machine manufacture. For example, wdth a single perfected tubing 
machine, it is possible to make plain, corrugated and soapstoned tub- 
ing, solid cords, wagon tires, multiple tubes, wire and fabric insula- 
tion, etc. 

Staistdard Tltbuvtg Machiistes. 

A modern tubing machine of the standard type may be described 
as follows : 

The horizontal cylinder is solidly attached to a cast iron stand or 
pedestal. The inside is smooth finished and is usually lined with a 
bushing which can be replaced when worn. The cylinder is chambered 
for steam and water for controlling the temperature. At its rear end 
is a solidly fastened bearing to withstand the heavy end thrust of the 
stock worm. 

The stock worm is a spirally grooved arbor working inside the 
cylinder, which kneads the rubber compound and forces it forward. 
Projecting through the thrust bearing, it extends beyond the machine 
to carry the driving gear. At the front end of the cylinder is attached 
the stock head, holding a removable die which forms the outside of the 
tube and also a sfuider for forming: the inside of the tube. This stock 
head is also chambered for steam and water circulation. There is also 



TUBE MAKING MACHINERY 



181 



attached to the frame of the machine an adjustable bracket, which 
supports on a roller the driving end of a delivery apron. This apron 
carries the tube away from the machine as it comes from the stock 
head. 

These machines are also built with a cylinder to hold powdered 
soapstone, with inlet and outlet for an air pipe which conveys the 
powder up through the machine head and to the inside of the tube. The 
dies and girders for forming the tubing are removable. 

Fig. 182 shows a longitudinal section of a tubing machine. The 
important parts are the steam chambered cylinder F ; the worm L, with 




Fig. 182. — Standard Tubing Machine. 



its thrust bearing shown at the right hand end; the head E ; the die B, 
and the core G. The rubber is fed through the opening A and is forced 
forward to the die B by the screw C, which is revolved by the gear D. 
The head E, to which the die is screwed, is bolted to F. A core G, fixed 
to the adjustable bridge H, projects into the center of the die. Steam 
or water is admitted to the chambers K in the screw casing and the die 
holder. 

The Royle Tubik^g Machine. 
Fig. 183 shows one of the later types of American tubing machines^ 
equipped with motor drive, heating and cooling compartments, soap- 
stoning tank and adjustable take-off mechanism. This machine, with 
various types of dies and die holders, is used for making rubber tub- 
ing, insulated wire, jar ring tubes, solid tires, and also for covering 
tubular fabrics. The head A and cylinder B are similar to those parts 
show^n in Fig. 182. The machine is driven by a motor C through a 



182 



RUBBER MACHINERY 



pinion D driving a spur gear E journalecl in the housing F. A pinion 
on this shaft revolves a large gear keyed to the worm shaft. The driv- 
ing gear is enclosed by a guard G to protect the operator. 

Tubing, as it issues from the die, is soft and liable to injury. 
Until vulcanized it must be handled with care to avoid stretching or 
deforming. The tube is therefore delivered upon a horizontal belt 
running over a pulley H directly in front of and slightly below the 




Fig. 183. — The Royle Tubing Machine. 



die. The pulley H is provided with a speed regulating machanism 
controlled by the hand lever I. Power for driving the apron is taken 
directly from the driving shaft extending through the housing F. 

To prevent the tube from collapsing and the inner walls from 
adhering to each other, powdered soapstone is forced into the tube as 
it is formed by compressed air. The soapstone is placed in the tank M, 
which has an air inlet N and a tube R for conveying the soapstone to the 



TUBE MAKING MACHINERY 



183 



die. The tank is only partly filled with soapstone, leaving a generous 
air space. As the soapstone mixes with the air it is carried to the die 
and blow^n into the tube as it is formed. 

Motor Drive. 
As in other branches of the rubber industry, motors are fast tak- 
ing the place of belts for tubing machines. The best method is to make 
the motor and machine a unit by mounting both upon a sub-base and 
driving through positive gearing from the motor to the driving pinion 
of the machine. The sizes of motors vary. For the smallest machine, 
making tubing % inch in diameter and under, a motor of 2 to 4 
horse-power is required; for a machine making tubes up to 1 inch in 
diameter, a 5 to 8 horse-power motor is employed. Machines making- 
tubes up to 3 inches in diameter require a 15 to 18 horse-power motor. 
Larger machines, for jar ring stock, solid vehicle tires and large sizes 
of hose lining, require a 20 to 25 horse-power motor. 




Fig. 184. — Allen Double Tubing Machine. 



184 



RUBBER MACHINERY 



The Allen Double Tubixg Machine. 
The iVllen machine, shown in Fig. 184, is really two machines in 
one, the cylinder A containing a right and left worm B. When rnbher 
stock is fed into openings C and D, the worm forces the stock to the 
center and ont through the die in head E. A chest F provides steam 
and water connections for heating or cooling the stock as it passes 
through the chambered cylinder. The shaft of the worm extends 
through the end bearings and carries a fly wheel G at each end. The 
worm is bored for water circulation. The machine is driven by an 
electric motor J through reducing gears, which are enclosed in the 
case K. 

The Kay Tubixg Machixe Feedee. 
Fig. 185 illustrates a tubing machine equipped with a pair of 
feeding rolls, which force the rubber into the cylinder more quickly 




Fig. 185. — The Kay Tubing Machine Feeder. 



and under pressure. The cylinder A and feeding screw B are prac- 
tically the same as in the ordinary tubing machine. The feed rollers 
C are placed on the cylinder above the feed opening D and are inclined 
at an angle of about 30 degrees to the horizontal, to reduce friction. 
The hopper D is made equal in length to the diameter of the cylinder 
A and equal in width to the pitch of the worm B, thus providing uni- 
form feeding. 

The Mahox'ey Striped Tubixg Machixe. 
Fig. 188 shows a device for making striped tubes. The machine 
has an outer cylindrical shell A, within which a sleeve B rotates. This 



TUBE MAKIXG 2IACHIXEEY 



185 



sleeve has a continuous spiral feed channel C. AVithin it is a second 
spiral feeder D, these two being separated bv a sleeve E. A chamber 
G receives the rubber compound forced into it from the groove C. A 
chamber iZ" receives the compound from the spiral feeder B. The die I 
is in the form of a plug with ribs which make it fit into the opening 
in the center of the die carrier. This leaves a space between these 
two parts, divided by the projections on the die and in the holder. 
Extending from the outside of the cylinder to the center of the die 
holder are four stems /. These have bevel gears il/ on their outer ends 
and are rotated by the bevel gear K on the outside of the casing. On 
the inner end of each stem is a stripe forming die projecting into the 
opening between the die holder and the die. Each of these stems 
has an aperture which, in a certain position, forms a continuation of the 
opening G from the feeder B to the die. 

Compounds of different colors are placed in hoppers and forced 
into the chambers G and H. Strips of one color are forced from the 
chamber H through the openings between the ribs of the die; strips 
of a different color issuing from the chamber G filling the spaces 
between the first set of strips. Thus, the machine assembles strips of 




Fig. 186. — Tubing Machine with the Kay Feed. 



186 



RUBBER MACHINERY 




Fig. 187. — The Bridge Tubing Machine Feed Open. 

compound of different colors, adhering at their edges to form a complete 
tuhe. To produce stripes with a wavy effect, the feeders are mounted 
so as to oscillate on their axes. 

The Vooehees Tubixg Die. 
In the manufacture of cheap tubing, particles of metal sometimes 
form defects or leaks. This is prevented in the die illustrated in Fig. 
189. The drawing' on the left is a longitudinal section of the head 
of a tubing machine. The lower drawing on the right is an enlarged 
section through the die, while the upper drawing is a cross-section. 
A is a worm which revolves in the cylinder B. C is a steam-jacketed 
head attached to B, supporting the die. D is ^ core-sustaining bridge 
fitted to the head C. This core-holder has a hub, connected to its outer 
rim by three arms, providing spiral passages for the rubber compound. 
The die E is held in position by the spacing block F and the nut G, 



TUBE MAKING MACHINERY 



187 




Fig. 188. — The Mahoney Striped Tubing Machine. 



these parts being centered by set screws -/. A core H is screwed into 
the core-holder D and projects into the die E. A tapering circular 
thimble / is located in the passage through the forming die. This 
thimble divides the rubber compound as it is forced through the die, 
forming two tubes. After passing- the thimble the two tubes are united 
J ^L 





Fig. 189. — The Voorhees Tubing Die. 



ISS 



EUBBEB 21 AC my FRY 



into one. Any particles of foreign material are tlins confined to the 
inside or the outside tube and cannot extend more than half wav 
through the total thickness of the finished tube. 

The Dewe Hammeeixc^ Machine. 
The machine, illustrated in Fig. 190. forms a strip of sheeted 
rubber into a seamless tube by drawing the edges together over a man- 
drel and joining them by a series of rapid blows delivered hy a small 
trip hammer. With freshly cut stock a seam may be made ^vithout 

^ B 




Fig. 190. — The Dewe Hammering ]\Iachixe. 

cement which will withstand as much strain as any other part of the 
tube. The machine Avill produce either butt or lap seam tidjes. The 
tube is started over the mandrel by hand and the hammer ^-i set in 
motion through belt pulley B. As the hammer welds the seam, the tube 
is pulled through C in the plate B. This plate has eight openings for 
tubes of as many different sizes, and other plates may be substituted for 
other sizes of tubing. The machine shoAvn occupies a space about a foot 
square and stands about 26 inches high above the table. 



TUBE MAKING MACHINERY 



189 



The Turnee Tubixg Maciiixe. 
The Turner machine for forming a strip of sheeted rnbber into 
a tube and cutting it into lengths, is illustrated in Fig. 191. Strips of 
rubber of a proper width, and with edges solutioned, are fed into the 




Fig. 191. — The Turner Tubing Machine, 



machine on the upper surface of the belt A. They are passed around 
the drum B, through a closing die at 0, where the edges are abutted, 
closing the strip into a tube. The tube then passes through the presser- 
roUs I and J , which roll the seam down. From the presser-rolls it is 
fed to the cutters Q, which are operated intermittently by cams and 
cut the tube into the required leno;ths. From the cutters the tubes are 
carried forward upon the belt H to any convenient point. 




Fig. 192.— Multiple Tube Machine. 



190 



RUBBER MACHINERY 



Multiple Tube Machine. 
The machine shown in Fig. 192 forms a number of tubes on 
wire cores at one operation. The wires A are drawn oft' from the reels 
B and pass over the guide pulleys C and D to the grooved rollers E 
and F, several w^ires being used in each groove to form the complete 
core. The rollers E and F have a number of grooves of suitable size 
for the outside diameter of the tubes to be formed. The cores A and 
the upper and under covering strips of rubber pass through the grooved 
rollers E and F. This presses the upper and under strips firmly 
together, resulting in a series of tubes, each surrounding its core. The 




Fig. 193.— The Bowley Tubing Machine. 



TUBE MAKING MACHINERY 



191 



tubes G thus formed are guided over the pulleys H and / to take-up 
drums /. They are then vulcanized, after which the wire cores are 
withdraw^n., The upper and under strips should be of the proper 
width to extend over all the cores and fed in a single sheet. The draw- 
ing on the right of the rollers E shows the wire cores A and the method 
of pinching the edges of the rubber strips together to close the seams. 

The Bowley Tubing Machine. 

Fig. 193 relates to a method of forming rubber tubing and cur- 
ing it by the cold-cure process. It consists first in dissolving rubber in 
bisulphide of carbon and adding chloride of sulphur. The drawing 
shows an apparatus for producing rubber tubing from this solution. 
The mixture is compressed in the cylinder A and forced into the cham- 
ber B through the stop cock C. As the rubber is compressed in B it 
is forced downward between the die D and the core E, thus form- 
ing the tube F. When the piston G reaches the end of its stroke the 
stop cock C is closed and a fresh supply of rubber is drawn into the 
cylinder A from the supply tank H. 

The rubber tubing F emerges in a sticky condition. To remove 
the surplus solvent from the tube, a current of warm air is passed 
through the pipe -/ and escapes through an opening in the plug K. 
The opening is regulated by a stop cock L so that the air will flow 




Fig. 194. — The Birmingham Stock Shear. 



192 



RUBBER MACHINERY 



through the tube at such a rate as to keep it from collapsing. To remove 
the stickiness of the inside walls, powdered chalk is mixed with the 
air and blown throuaii. 



for cuttino; tubing and small mold 



The Birmingham Stock Shear. 

Fig, 194 illustrates a shear 
stock. The cast iron frame is bolted to a bench and has two uprights 
in which swing two levers pivoted to each end of the shear knife. 
This is operated either by hand or foot lever. A hard wood strip pro- 
tects the cutting edge. 

The Excelsior Stock Cutter. 
The machine shown in Fig. 195 cuts tubes or round stock in short 
lengths. The two side-frames and table grooved for ten tubes are 
bolted together and support the feed rollers, cutting knife, and the cam 
and driving shaft. The machine is bolted to a table and is belt driven. 
On the drive shaft between the frames is a cam that operates the cut- 




FiG. 195. — The Excelsior Stock Cutter. 



ting knife. On the end of the drive shaft is a cam that operates the 
feed rollers through adjustable levers and a ratchet wheel. The stock 
is fed forward the required distance by the feed rollers. The cam on 
the driving shaft operates the reciprocating knife which cuts oif the 



TUBE MAKING MACHIXERY l^ 

stock. The operation of the machine is continnous and rapid. It can 
be adjusted to cut off various lengths of stock. 

The Holmes Stock Cuttee. 
Fig. 196 shows a three-speed power cutter, for cutting stock from 
a tubing machine into suitable lengths. The rapidly revolving canv 
shaped knife severs the stock with a shearing cut. The stock is fec^ 




Fig. 196. — The Holmes Stock Cutter. 



through a die against a stop which determines the length. Several dips, 
for various sizes and shapes of stock, are shown in the illustration. 
The device cuts any size up to 1% inches in diameter and 2% incjips 
long. The capacity is from 9,000 to 15,000 pieces per hour. 



CHAPTER XII. 

SPEEADEES, DOUBLEES A^^D SUEFACE EIXISHEES. 

SPEEADIXG or knife coating is a process in wliicli a thin coating 
of rubber in solution is applied to one or both surfaces of a sheet of 
fabric. The equipment of a complete coating or proofing plant con- 
sists of washers, dryers, mixing mills, churns, spreading, doubling and 
measuring machines. The vulcanizing equipment consists of a dry heat 
vulcanizer for single and double texture fabrics and a vapor vulcaniz- 
ing chamber for electric finished single texture surface fabrics. The 
spreader in general consists of an iron frame, a steam table for expell- 
ing the solvents, brackets and take-olfs for cloth in the roll, rollers for 
supporting and guiding the cloth and an adjustable horizontal knife 
under which the cloth passes. Against this knife the rubber solution 
is fed, only a thin coating of which passes under it with the fabric. 

The Haxcock Speeadee. 

From the time of Hancock there have been scores of dilferent 
spreaders invented, most of them based upon the general principles 
outlined above. Hancock's spreader is briefly 



as 



follows : Eef erring 




^ ^/////// / // } 
' ^/^^^//^/// ) 




Fig. 197. — The Haxcock Spreader. 



to Fig. 197, A is the frame of the machine. B is the spreading knife 
and C is one of the two side brackets which support the knife. T) is 
one of two screws for adjusting the knife and E the set screw for fas- 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 195 

tening it in place. F is one of the two solution guides, G is the rubber 
dough, H is R hollow steam heated plate and I is a steam heated drying 
table. '/ is the fabric supply roller and K the take-off roller upon 
which the coated fabric is w^ound. 

The spreading knife B is hollow and heated by steam. Its edge 
is not sharp but somewhat rounded. It is adjusted vertically by the 
screws D and kept in place by screws E. The edge is perfectly straight 
and accurately in line with the bed plate H. That part of the plate 
H which is directly under the knife B is raised a little above the level 
of the bed and is three or four inches wide, flr.t and smooth. The knife 
B is screwed down to the bed plate H, leaving an open space equal to 
the combined thickness of the fabric and the required film of rubber. 
The rubber dougli is prevented from spreading beyond the width of 
the cloth by the guides F. The fabric to be proofed is rolled up on the 
feed rollers J and the free end passed under the spreading knife and 
attached to the take-off roller K. The knife B and the bed plate H are 
maintained at a temperature of 85 to 100 degrees F., while the steam 
table I is kept at 100 to 150 degrees F, 

The Staxdaed Spreadei?. 
Spreading machines are used for proofing textile materials with 
rubber for a great variety of purposes, but mainly for clothing, proof- 



MQH 


ESS^^ 


*?, 


^^^^ 


Jh ^jK^JTwI"'*^^^ 


^—.-^ 


•^ 




^^^ 


^~ 


W^ 


^ 



Fig. 198. — The Standard Spreader. 



ing, etc. Standard spreading machines are built in widths from 50 
to 71 inches and comprise two side-frames of cast iron with cross 
pieces to hold them rigidly in place. At the front end of the side- 
frames are openings to receive the journal boxes which support a hoi- 



196 BUBBEB MACHIXEBY 

low roller with a spur gear on one end. This is driven hy a pinion on 
a counter shaft. This counter shaft, which is journaled in bearings 
attached to one of the side-frames, has a three-speed cone pulley driven 
by a belt from an overhead counter shaft. At the front end of the 
side-frames are bearings to support a square arbor which holds the roll 
of cloth, also a friction let-olf to provide tension on the cloth as it 
passes through the machine. At a short distance back from the front end 
of the machine is a wind-up roller similar to the let-olf, but driven by 
belt from the drive roller. At the back end of the machine is a roller 
driven at the same speed as the drive roller by means of bevel gears, and 
a long shaft extending from the front to the rear of the machine. A 
bevel gear on the back of this shaft meshes with a bevel gear keyed to the 
back roller which drives it whenever the front roller is in motion. 

Above the front roller is a steel knife, which is supported in 
brackets bolted to the side-frames. The lower edge of this knife is 
adjusted to a rubber covered roller and forms a trough with the sur- 
face of the fabric for one side and the knife for the other side. This 
is adjustable vertically by means of screws and hand wheels in the top 
of each side bracket. Guides are also attached to keep the solution 
from running over at the sides. These guides are adjustable and can 
be set any distance apart. A series of steam plates is attached to the 
top of the side-frames extending from the front to the rear of the 
machine, forming one continuous steam heated table from 12 to 21 
feet long. 

Short length spreading machines — say 15 feet froni the rubber- 
covered roll to the wood <lrums at the other end of the machine — are 
not used in the production of single texture surface goods, for the 
reason that the successive coatings do not thoroughly dry out before 
the coated surface reaches the wind-up roll. Spreading machines 30 
feet in length are preferable. The evaporating surface of the steam 
heating coil is double that of the short length machine, greater speed 
in running and greater yardage are also produced. The damage from 
fire caused by electric operation, which igTiites gasoline vapors pocketed 
imderneath the machine, between the rubber-coated roll and the wind- 
up roll, is also practically eliminated. 

Where space is valuable and high steam pressure available, short 
spreaders are. however, used successfully and the solvent forced out 
before the fabric reaches the wind-up. 

In spreading, the coating material or dough is made of rul^ber 
compounded on a mixing mill and then blended with naphtha or other 
solvent in a cement churn. The operation of the spreader is as follows : 



I 



SPREADERS, DOVBLERS AND SURFACE FINISHERS 197 

A roll of cloth is placed in the let-off bearings at the front of the 
machine. Attached to the free end of the cloth is a temporary apron 
long enough to extend the entire leng1;h of the machine and back under- 
neath to the wind-up roll near the front end. When the apron is 
attached to the wind-up roller, the clutch on the driving shaft is thrown 
in, and the machine is started. As soon as the temporary apron has 
passed by the knife the machine is stopped and a batch of dough is 
placed before the knife and the machine again started. 

This coating material rests on the cloth above the rubber covered 
roller, and the cloth passes under the knife, leaving only a thin lilni 
on the fabric. As the cloth passes over the steam table the heat evap- 




FiG. 199. — The Frankenstein-Lyst Spreadee. 



orates the naphtha, and the proofed fabric is rolled up on the wind-up 
roller. If a heavier coating is required the spreading operation is 
repeated until it is of sufficient thickness. There is no standard for 
the speed of a spreading machine as it is arranged to suit the stock to 
be proofed. A low speed of 10 or 15 yards per minute often will give 
better results than a higher speed. The standard spreader as described 
above requires about 5 horse power to operate. 

In the early days of proofing, fires w^ere of frequent occurrence. 
A simple device for discharging the frictional electricity consists of 
copper strips to which are soldered needles that are set just below the 
guide rollers, but not close enough to tear or mark the fabric. A con- 
ductor wire is attached to this device and grounded, usually in water 
or on a pipe running into the earth. A perforated pipe near the rubber 
covered roll, through which live steam is forced, is also employed to 
guard against such fires. 



198 



RUBBER MACHINERY 



Of special horizontal spreaders there are an infinite variety, the 
majority being of English origin. The departures from the standard 
type are in the line of unusual knives, oddly placed drying drums, cool- 
ing rolls and automatic solution feeds. There are also types that 
spread two sheets of fabric side by side ; others that have a num- 
ber of solution knives. There are double, triple and quadruple 
deckers, all for proofing fabrics with rubber. There are, too, as 
many more for proofing and varnishing paper and for spreading a 
great variety of waterproof compound in which no rubber appears. 
The following, selected from those used for rubber, are typical. 



I 



The Feaxkexsteix-Lyst Speeadee. 
In the Frankenstein-Lyst spreaders. Tigs. 190 and 200, there is 
one spreading roller A and four knives. The fabric is first coated 
lightly in an ordinary spreader and thoroughly dried. This coated 




Fig. 200. — The Frankenstein-Lyst Spreader. 



fabric then has a thick coating of rubber dough applied to it by the 
first knife; the others, which are set successively closer to the roller, 
compress the dough and remove the surplus. The fabric is supplied 
to the spreading knives from the roller E. The shaft F drives the 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 199 

wind-up roller at the opposite end of the nxachine. After passing over 
the drying table D the material is finished by calendering rolls, placed 
at the opposite end. 

The Eowley-Walmsley Spreader. 
The Kowley-Walmsley machine, shown in Fig. 201, is a spreader 
of the double deck type. There are two spreading knives at each end 




ijiS 






m 




Fig. 201. — The Rowley- Walmsley Spreader. 

of the machine, two rolls of fabric being coated simultaneously by one 
operator. The reversing device is very simple and it is claimed that 
by thus spreading the dough in alternate directions, liability to porosity 
is eliminated. Thus, the winding back and handling of the rolls of 
fabric as in the ordinary machine is avoided. The two drying tables 
are each 20 feet long, which has been found sufficient to expel the 
solvent when the cloth is passed at the rate of 8 to 10 yards per minute. 
The spreader rollers are faced with rubber and are 10 inches in 
diameter. The machine is 10 feet wide and 27 feet long over all. 

The Salisbury Spreader. 
The Salisbury machine, shown in Fig. 202, gives the fabric two or 
more successive coatings of rubber in one operation and dries each coat- 
ing before the next is applied. In the drawing A represents the frame 



200 



RUBBER M AC H IX FRY 



of the macliine that carries the fabric roller B, which is provitled with 
a spring controlled brake C. The fabric, indicated at X, passes from 
the roller B and over a roller D. Above this roller is a spreading knife 
E adjusted vertically by the screw G. 




Fig. 202. — The Salisbury Spreader. 



Located above this first proofing device is a second one just like 
it, consisting of the roller H and knife I. That the fabric, in passing 
from roller D may have sufficient time to dry, it is passed over steam 
coils ^y by a series of rollers /, K, L, 21 and X. A third roller and 
knife are located above I for applying a third coating to the fabric. 
Since the second coating requires less time to dry than the first, the 
travel distance between the second and third coating devices is less than 
between the first and second. Accordingly, the fabric passes over 
rollers Q and R and thence over roller to receive a third coat, after 
which it is led over guide rollers S and T to the windup roller U. 
Where only two coats of rubber are applied, the fabric is passed from 
roller Q to roller V, thence around roller T to take-up roller. 



SPREADERS, DOL'BLERSAXD SURFACE FINISHERS 201 



Fig. 



The Wood-Robixsox Speeadee. 
203 shows the Wood-Robinson spreader. The fabric is proofed 
from both ends, and dried bv two steam heated cylinders placed between 
the spreading rollers. After leaving the spreading roller, the cloth 
passes nearly aronnd the cylinder nearest to it, and is conducted by 
four guide rollers to the second cylinder, passing around it in the same 
manner and then to the wind-up roller. The time required to reverse 
and prepare the machine for the return coat is two minutes. Referring 




Fig. 203. — The Wood-Robixsox Spreader. 

to the drawing, the fabric A passes from the delivery roller B over the 
spreading roller C and under the knife D. Then the coated fabric 
passes almost entirely around the drying cylinder E, over guide rollers 
F, and around a second steam heated cylinder G. The spreading 
knife H is thrown out of operating position and the proofed fabric is 
wound up on the roller I. If a second coat is to be applied, the knife 
H is thrown in and the knife D throwm out, after which the fabric is 
run back throu2:h the machine in the manner alreadv described. 



The Coultee Reveesible Speeadee. 
The Coulter machine, shown in Eig. 204, is another type of double- 
ended spreader. The machine comprises the end frames A and B car- 
rying spreading knives C and D, and spreading rollers E and F. There 
are also central frames G under the steam heated drying table H. The 
fabric / passes from the roller -/ over the drum K and receives the first 
coat of rubber solution at D and F. It then passes over the heating 
table, the spreading knife C and roller E being out of operation. It 
then passes over the drum L to the wind-up roller M. The drum E is, 
in this case, out of gear and the cloth is dra"\\m through the machine by 
the roller M. The drums K and L are steam heated and are made of 



202 



RUBBER MACHINERY 




Fig. 204. — The Coulter Reversible Spreadir. 

sheet metal. The machine is reversed for the second coat, which is 
applied at the opposite end of the machine. 




^^^^^ 




^ftr-—i] 



I Ul 



ffil 



^ 



H 



G 




Fig, 205. — The Birley-Macintosh Spreader and Stretcher. 



SPREADERS, DOUBLERS AXD SURFACE FINISHERS 203 

The Bikley-MacixtOoIi Speeader and Stretcher. 
Woven fabric decreases in width when bleached or dyed, and if 
it is stretched before proofing it shrinks again during the spreading. 
The Birlev-Macintosh spreader, Fig. 205, stretches the fabric in the 
-direction of its width while on the spreading machine. The cloth to 
be proofed is unwound from the brake roller A and is drawn over the 
spreader roller and under the gage C in the usual manner. It passes 
in the direction indicated by the arrows, over a series of steam heated 
plates B forming the drying table. Kunning lengthwise of the machine 
are two guide rails D which are adjusted laterally by cross rods E 
attached to F F. The rods have right and left hand screw threads 
which engage nuts in the guide rails. The edges of the fabric are 
fastened by clips to the endless chains G driven by sprockets H. By 
means of the adjustable guide rails and screw rods the cloth is stretched 
as it passes over the heated table. 

The ]\Ian]n" Spreading IIachike. 
The Mann machine, shown in Fig. 206, spreads several coats of 
rubber on the fabric while it travels in one direction. For example. 







Fig. 206. — The ]Maxx Spreading Machine. 



if it is desired to give six coats of waterproofing material to a piece of 
fabric, the cloth is passed through the machine, as usual, from a batch 
roller, and its end is fastened to a leader which is threaded through 
the machine. But instead of winding; up the fabric after receiving 
its first coat, it is folded on a traveling table by a plaiting-down mechan- 
ism until all the fabric is unwound from the batch roller, after which 
the two ends are joined and the fabric is run through the spreader any 



20^ BUBBEB MACEIXEBY 

desired nimiber of times. Referring to the drawing, A and B represent 
the front and rear ends of the machine. The fabric C to be coated is 
iinwonnd from the roller D, passes over an idler roller E and around a 
brake drum F. From this it passes over a guide roller and under the 
knife Cr and then over the steam heated table H. Instead of being- 
wound up at the end of the machine, the fabric passes aroiuid a drum /,, 
over an idler roller -/ and between a pair of rollers K. From this point 
the cloth is run through a folding mechanism, which consists of a pair 
of rollers L on the lower end of a swinging arm J/. This is rocked 
back and forth by a connecting rod X and the crank 0, which lays the 
fabric down in loose folds upon the traveling apron F. that moves in 
the direction of the arrows. When the forward end of the fabric 
reaches the front of the machine the material is nearly im. wound from 
the roller D. This end is brought down from roller E, around bar Q, 
roller B and bar Q. At this point the two ends are joined and the 
belt of cloth is run through the spreader im^til the desired niunber of 
coatings are applied. 

Veetical Speeadees. 

The vertical spreader is essentially a French invention and is used 
more in French practice than in any other. It has. nevertheless, been 
adopted in both England and Germany, and types of machines that vary 
somewhat from the French pattern are manufactured in both the coun- 
tries named. The original vertical spreader was the Decauville. It 
came into use as a labor saving device. Passing the fabric over 
through the machine proofed and dried both surfaces. The machine 
is really both impregnator and spreader. The fabric starting at the 
bottom, is run through a tank filled with rubber solution, then between 
squeeze rollers which remove much of the dough on the surface, the 
remainder being removed by spreader knives. After that the coated 
fabric passes iip and between steam heated plates built vertically at 
the top and down one side to the wind up. The plates are arranged 
in frames and can be moved quite close together or drawn some 
distance apart by a simple mechanical arrangement. 

Recent machines have arrangements for carrying away the naphtha 
fumes and condensing them for re-use. 

The Decaevieee Veeticae Speeadee. 

The Decauville vertical spreading machine is shown in Fig. 207. 

The fabric starts at the ];>ottom of the machine and lioth sides are spread 

at once. It is then passed between the two vertical drying tables A and 

B heated by steam pipes C. The tables are about 12 feet in height, so 



SPREADERS, DOUBLERSAND SURFACE FINISHERS 205 




The Decauville Vertical Spreader. 



that the fabric coming out at the upper end of the machine is per- 
fectly dried. It is generally run twice through the impregnating tank. 
Such machines are built for anv width of fabric from 56 to 96 inches. 



Geemax Vertical Spkeadek. 
The vertical spreader shown in Fig. 208 comprises two steam 
heated tables A and B with corrugated surfaces, and made sectional, 
heated by steam pipes C. The tables are braced and supported by a 
cast iron frame. The fabric, after passing from the let-off roller 
through a tank D of rubber solution placed imderneath the machine, 
])asses between squeezing rolls which are adjusted by the hand wheel 
E. It then passes to the top of the machine over the surface of the 
heated table, over guide rollers F and G, and descends to the opposite 
side of the machine, where it is wound up on the roller H. If the 
fabric requires a longer time to dry, it can be passed over the inside 
of the heated plates as well as the outside. The machine is made for 
coating fabrics up to TO inches in width. 



206 



RUBBER MACHINERY 




Fig. 208. — German Vertical Spreader. 



English Vertical Speeader. 



Fig. 209 shows an English vertical spreader, in wliicli the fabric 
passes from the brake roller B around roller / and between the spread- 
ing roller C and knife D, thence to the top of the machine aronnd a 
steam chamber E which dries it. It then passes down to the wind-up 
roller F. Motion is imparted to the fabric by chains G, which drive a 
roller at the top of the frame. These chains have hooks which engage 
the fabric when starting it through the machine. When the cloth has 
received one coat it is wound up on the roller F. The fabric is then 
passed around roller / and spreading roller C. The gage li is placed 
in operation, the gage D is thrown out and the direction of the machine 
is reversed. At the same time the brake K is shifted to the roller F. 



I 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 207 

For doubling, a supplementary roller L is provided on both sides 
of the machine for the lining cloth. The proofed cloth is wound on 
the roller B. The ends of the two fabrics are brought together around 
the spreading roller C under a pressure roller placed above the roller C 




Fig. 209. — English Vertical Spreader. 



and down the opposite side to the wind-up roller. The belt M is slack 
so that it will slip, as the speed of the wind-up roller must decrease as 
the fabric is wound on it. 



The Howkix Rollee Spreadee. 
The Howkin spreader differs from the usual type in that the 
knife is replaced by a roller driven at a diiferent surface speed from 
that of the main roller and is pressed against the latter by adjustable 
weights. The drawings, Fig. 210, show a front elevation and an 
enlarged, part side view of the machine. The spreading roller A is 
placed above the main roller B and is pressed down upon it by weighted 



208 



RUBBER MACHINERY 



levers C which rest on sliding bearings D. The rollers A and B are 
connected by a belt E and a train of gears F, G and H. The spread- 
ing roller A may be raised for cleaning or for passing the fabric 
between the rollers by hand levers J. In order to prevent the solu- 
tion from flowing over the sides of the fabric, gages K are provided on 
each end of the cross bar L. The roller A can be adjusted for different 
fabrics and thickness of the waterproofing material. The pressure 




Fig. 210. — The Howkin Roller Spreader. 

of roller A upon the fabric may be varied by sliding the weight M 
back and forth on the lever C. 



Coated Fabric Dkyee. 
An unusual type of apparatus for drying coated fabrics is shown 
in Fig. 211. The drawing shows the fabric A coming from the spreader 
B and passing through the dryer. The latter comprises a long casing 
divided into compartments C, D and E. In the first and last of these 
compartments are rotating drums F and G carrying an endless con- 
veyor H. A blast of hot air is supplied to the dryer by a flue / com- 
municating with the compartment E. After passing over the fabric 
in this compartment, the air is exhausted by a fan / through the flue 
K into compartment D. It is then exhausted by another fan L through 
the flue M into compartment C. As the air passes through the sue- 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 209 



lir 







r f^^r"^-);X 



iiy!i 14 



.^ 






Fig. 211. — Coated Fabric Dryer. 

cessive compartments it becomes more or less saturated with moisture 
when it is finally exhausted into the atmosphere. The fines N and 
leading from fine / are provided with dampers to regulate the hot air 
supply in compartments C and D. 

The BeidCtE Polishixg, Cueixg axd Pastia^g Machine. 
The apparatus shown in Fig. 212 is really a combination of three 
machines in one. It consists of two independent machines A and B 
placed a short distance apart and a wooden drum C fixed to the ceiling. 




Fig. 212. — The Bridge Polishing, Curing and Pasting ^^Iachixe. 



210 RUBBER MACHINERY 

When the machine is nsed for polishing cloth, the fabric is wrapped 
on the brake roller D. It then passes under a rubber faced doctor E, 
in front of which the polishing material is placed. The lever F which 
controls this doctor is shown in its raised position, its operating posi- 
tion being indicated bv the dotted lines. From the doctor the cloth G 
passes over the drum C and down to the steam heated drying cylinder 
H. The fabric passes half-way around this cylinder and then over a 
guide roller I, after which it is wound upon a wooden roller •/. This 
roller is driven by frictional contact with the drum K which is driven 
by a spur gear and a pinion on the main shaft. This is driven by belt 
pulley L. 

AVhen the machine is used for curing, the proofed cloth on the 
roller M passes under the guide rolls N and 0, over a slate roller in 
the tank P. This roller revolves in the vulcanizing solution which it 
distributes over the surface of the fabric. On the side of the tank 
is a lever Q, by means of which the fabric may be lifted out of contact 
with the slate roller. After being treated, the fabric, which is indicated 
by the line R, passes to the top of the frame and across to the heated 
cylinder H. After passing slowly around this cylinder until it is 
cured, the fabric is wound up in the same manner as described above in 
the polishing process. 

When the machine is used for pasting, the fabric is wound by 
hand from the roller M, over a steam heated pasting tank fixed to the 
top of the frame at S, and then to the roller D. When all the cloth 
is on the front roller it is ready for polishing or curing as described 
above. 

Chalkia'g Machixe. 

The chalking machine shoT\Ti in Fig. 213 is used to prevent the 
cloth from sticking to the rubber stock. The fabric is wound on a 
roller B which is provided with a brake. The top of the frame car- 
ries a chalk box E in which revolves a brush extending the full width 
of the machine. This spreads the chalk evenly over the surface. At 
the other end the fabric is wrapped upon another roller which is driven 
by the belt C through a pair of spur gears. This roller is mounted on 
the same shaft with the gear D. Carrier rollers are fixed to the top 
of the frame to give the fabric the necessary tension over the chalking 
roller and the brushing roller F. The latter removes the surplus chalk 
and is usually enclosed in a box. 

The Sqeiees Starchixg axd Cleaxixg Machixe. 
In Fig. 214 the rear end of a spreading machine is shown, 
equipped for starching, cleaning by vacuum and brushing single texture 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 211 




Fig, 213. — Chalking Machine. 



goods. The goods are spread at the front end of the machine and pass 
over a steam heated table and nnder the starch er A. Snrplns starch 
is removed by the motor driven vacuum cleaner B and the revolving 
brush C and deposited in the box D. The starch is dried and stored in 
the steam heated dryer E. 




Fig. 214. — The Squires Starching and Cleaning ^Machine. 



212 



RUBBER MACHINERY 



The Bekry Printing Machine. 
In color printing on the rubber surfaces of waterproofed fabrics, it 
was formerly customary to first apply farina to hold the color. Berry's 
machine eliminates this necessity by spreading a thin film of water 
over the rubber before it enters the printing machine. The apparatus 
comprises four rollers revolving in troughs of water, and a means of 
keeping the fabric under tension as the water is being applied. Refer- 
ring to the drawing, Tig. 215, upon the frame A are mounted two metal 
troughs B and (7, in which reyolve four copper rollers D and E, and F 
and G. The troughs are fitted with a water inlet pipe H and outlet 
pipe / by means of which a constant water level is maintained in the 
troughs B and C. The trough C is fitted with an overflow pipe / con- 
necting with the outlet pipe /. The fabric K enters the machine in 
the direction of the arrow and passes over the loose roller D. The other 




Fig. 215. — The Berry Printing Machine. 

three rollers are driven by gearing in the opposite direction from that 
of the fabric and spread a thin film of water over the rubber surface. 
Each of the gear-driven rollers has a friction clutch so that it may be 
thrown in or out of engagement with the driving chain. Between the 
troughs is placed a transverse bar L under which the cloth is passed. 
When this bar is lowered by the adjusting screws M the fabric is 
brought in contact with the wet rollers. In addition to this bar, small 
drag rollers iV^ are placed at either end of the machine. The frame of 
this apparatus may be attached directly to the printing machine or at 
some distance away from it, the fabric being led directly from the 
troughs to the printing rollers. 



The Hodgman Dull-Finish Machine. 
The apparatus shown in Fig. 216 is designed for finishing rubber 
coated fabric with a dull surface as distinguished from glossy and 
other finishes. Usually, as the rubber coated cloth comes from the 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 213 

calender rolls, it has a tacky surface and is sprinkled with flour, starch, 
soapstone or other suitable powder in order that it may be handled. 
After vulcanization the cloth has to be thoroughly scrubbed in order to 
remove the surplus powder, after which it must be dried in the air 
to remove the slight tackiness which still remains. This produces a 
dull finish. But the object of Hodgman's apparatus is to produce the 
same finish without requiring the cloth to be scrubbed and sun-dried. 
As the rubber cloth comes from the calender rolls A, it 
passes over a guide roller B and under a powdering roller C. 
The flour or other powder is placed over the roller C and a blade 
D serves to keep it in contact with the fabric. After leaving the 




Fig. 216. — The Hodgman Dull-Finish Machine. 

powdering device, the cloth passes over brushing rollers E and a 
series of guide rollers F. Then with the powdered side down, 
it is passed over a varnishing or inking roller G which revolves 
in a solution of rubber, benzine or naphtha and lamp black. 
This prepares the surface so the cement used for seams will readily 
adhere to it. From the varnishing roller the fabric passes over rollers 
H, I and J, and then to the wind-up roller K. In order to prevent the 
cloth from moving with a jerky motion and to compensate for the 
increasing diameter of the wind-up roller a speed-regulating and brak- 
ing device is employed. From the varnishing roller the fabric passes 
over the roller H, which is covered with emery to provide friction. 



214 



RUBBER MACHINERY 



This roller is driven by a belt L which is driven from a variable speed 
device M controlled by the belt shipper N. 

The Wood Automatic Solution Guide. 
The Wood solution guide, Fig. 217, is designed to compensate for 
the side creeping of the fabric and is so constructed that the side plates 




Fig. 217. — The Wood Automatic Solution Guide. 

follow the fabric, thus keeping the solution in place. The drawings 
show respectively, from left to right, a sectional end view and a front 
elevation of a spreader equipped with the device. 

In place of rigid angle brackets there are two sliding or traveling 
carriages A, which move in slot B. The carriages are made just tight 
enough by studs C, so that the friction prevents them from moving under 
the pressure of the proofing solution placed between the solution plates 
D. Through a tubular part H of each carriage A, passes short rocker 
shafts I, carrying rocking cranks / on their outer ends and pawls K on 
the inner ends. Each pawl has two horns L and M, one of which is off- 
set, in order to engage the oppositely toothed ratchet racks N and 0, 
Rods P, pivotally attached to the adjustable bracket A, engage with 
the cranks J on the rocker shafts J. Plates Q attached to the lower 
ends of the rods P, lie parallel and close to the edges of the fabric, 
and are moved by the fabric if the latter gets out of its normal align- 
ment. Flat springs R engage the underside of pawls K and tend to 
move the crank pins 8 and top of rods P downward, as regards the 
fabric T. They also tend to move the plates Q inwardly until they 



SPREADERS, DOUBLERSAND SURFACE FINISHERS 215 

come in contact with the edge of the fabric. The two oppositely toothed 
racks N and above the pawls K are fastened together and slide back 
and forth in bearings. The racks are vibrated or reciprocated by means 
of a small gear U having an eccentric hub on the inner end, which 
reciprocates the racks by means of a link V and bell crank lever W. 
The fabric passes over the rollers X and Y, and nnder the gage Z. 
The sliding carriages A are set the proper distance apart and plates D 
adjusted to the fabric. 

When the machine is running, the springs R keep a suitable pres- 
sure under the pawls K and the plates Q are lightly pressed against the 
edges of the fabric T. If the fabric creeps sidewise and moves away 
from one of the plates Q, the horn M on the pawl engages with the 
vibrating rack on that side of the machine and remains in this posi- 
tion until the sliding carriage A has been moved by the rack to bring 
the plate Q again in contact with the edge of the fabric. This brings 
the solution guides D, the rod P and pawl K in their normal positions, 
when the carriages will remain stationary until the fabric again changes 
its aligTiment. When the fabric moves away from one plate Q it 
presses the plate on the opposite side, engaging horn L on that side 
with the rack N, causing the carriage and guides to move outwardly 
and remain in that position until plates Q again make contact with the 
fabric. Thus the two plates follow the fabric, keeping the solution 
guides in alignment with it. 



CHAPTER XIII. 

SPREADEES, DOUBLEES AXD SUEFACE FIXISHEES— 

(Continued). 

DOUBLIXG CaLEXDEKS. 

FOE many purposes, such as for double texture waterproof clotli- 
ing, ten']ais shoes, etc., the cloth is doubled upon a liuing; that is, 

the coated textile material used for the outer side of the article 
is lined with a thinner fabric. This is done after coating by a doubling 
calender, w^hich is usually constructed as f ollow^s : 

There are two side frames held in position by stretcher plates. 
In these housings are two rolls, one above the other. The lower roll 
is in fixed bearings while the upper is journaled in bearings that can 
be raised or lowered by screws and hand wheels at the top of the frame. 
There is also a spring adjustment of the top roll so that it does not 
have a positive alignment with the lower roll. On the rear of the 
housings are bearings for a square arbor with a wind-up mechanism 
like that used on the spreading machine. On the front of the frames 
are let-off bearings for two rolls of proofed cloth. 

The neck of the lower roll is provided with a spur drive gear 
which engages a pinion on a counter shaft underneath. On this 
countershaft is a friction clutch pulley, driven by a belt from an over- 
head shaft. The top roll is driven from the bottom roll by even spur 
gears at the opposite end of the rolls. The operation is as follows : The 
two rolls of coated fabric are placed in the let-off bearings at the front 
of the doubler. The ends of each roll are drawn between the doubling- 
rolls and attached to the wind-up arbor. The machine is started with 
the spring pressure of the top roll pressing the two fabrics together 
against the lower roll. This compresses them into one sheet of material 
having a rubber coating between the two sheets of cloth. 

Yeeticae DorBLiXG Calexder. 
In the Bridge doubling machine, shown in Fig. 218, the lower or 
drive roll A is driven by spur gear B meshing with a pinion on a shaft, 
which bears the cone pulley C driven by a belt from an overhead shaft. 
The top roll D is driven by spur gears from the drive roll, and is 
adjusted vertically by screws, on the upper ends of which are worm 
gears F operated by worms on the hand wheel shaft G. Attached to each 



I 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 217 

side of the machine is a set of let-off bearings H which hold the two 
rolls of coated fabric under tension, as the fabric is drawn through the 
doubling rolls A and D. A belt-driven wind-up roll I is mounted on 
one side of the frame to wind the doubled fabric into a roll after pass- 




FiG. 218. — Vertical Doubling Calender. 



ing through the machine. The doubling rolls are hollow and provided 

ith steam 
ordinarv calender. 



with steam and water connections J for heating and cooling, as in the 



HoEizoNTAL DouBLi:^rG Calender. 
The doubling calender shown in Fig. 219 differs from the usual 
type in that the rolls A and B are placed in horizontal alignment, 
instead of vertical. The rollers C and D, which hold the two rolls of 
proofed fabric, or one roll of fabric and one of rubber, are located on 
opposite sides of the machine frame E. The fabric from roller C passes 
over the roll A while that from roller D passes over the roll B, and 
meet between the rolls, where they are firmly pressed together. The 
fabric then passes under an idler roller F and is wound up on the 
take-up roller G at the lower end of the frame. This roller is driven 
by friction from roller H, driven by belt pulleys I and /. This machine 
is geared and driven very much like the ordinarv calender, and the 



218 



RUBBER MACHIXERT 




Fig. 219. — Horizontal Doubling Calexder. 

doubling rolls are provided with heating and cooling connections K 
in the usual manner. 



The Birxbaum Doublee. 
The drawing. Fig. 220. shows a side view of the principal parts 
of the machine. The cloth first receives a coating of rubber on the 
spreader and is then transferred to the doubling machine and wound 
up on the roller A. It then passes over a roller which revolves in a 
tank B containing naphtha or other rubber solvent. This renders the 

c 




Fig. 220. — The Birxbaum Doubler. 

surface of the rubber soft and adhesive. Any excess of moisture is 
removed by a roller C or a doctor placed across the machine and cov- 
ered with suitable absorbent fabric. The rubber surface of the cloth 
is then brought into contact with an uncoated lining D which is 
unwound from the roller B. These two fabrics are pressed together 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 219 

"between the doubling rollers F and G, and the completed double texture 
fabric H is then wound up on the roller I. It is important that no excess 
of moisture be present on the surface of the softened rubber which, if 
rendered too sticky, would be forced through the fabric lining and thus 
spoil the appearance of the finished product. 

Fabric Stripiis^g. 
There are many factories that proof cloth, cure and sell it in the 
roll to small concerns who do the making up. Such concerns have 
large plants and often devote themselves entirely to proofing for the 
trade. Proofed cloth is cured either in a dry heat vulcanizer or it is 
cold cured. The latter cure allows of many artistic effects in single 
texture goods that are not possible with the hot cure. A thin coating 
of transparent rubber over a figured fabric allows the pattern to show 
through, the colors being slightly toned down; that is, if the rubber 
be cold cured. Beautiful effects are also produced by dusting the 
surface with potato starch before applying the vulcanizing solution. 
This converts the starch into a translucent, silky film. By grooving 
the solution roller, stripes are formed upon such a surface. Two 
rollers grooved in spirals, whose grooves do not correspond, produce 
heautiful hazy lines. Ornamentation is also effected by spreading 
stripes of colored rubber upon the plain spread surface. The ornamen- 
fation, as a rule, is confined to lines. 




Fig. 221. — The Videto Striping Device. 



220 



BUBBEB MAC HI XE BY 



The Videto Steipixg Device. 
The striping apparatus shown in Fig. 221 consists of a semi- 
cylindrical trough A having a series of slots B cut through the lower 
side. Extending laterally from these slots are a nimiber of shallow 
channels C of different widths. The fabric is led over a roller D^ 
underneath the trough which contains the coating solution and over 
another roller E. As the fabric passes under the trough the rubber 
solution comes into contact with it and a thin film is deposited upon the 
fabric in stripes of a breadth equal to the full length of each slot B, 
the color of these broad stripes being a compromise between that of 
the fabric and of the rubber. A thicker film of rubber solution is 
left upon that part of the fabric which passes im.demeath the trans- 
verse channels C and a different color is therefore effected at this part, 
forming a striped effect as indicated in the diagram of the falrric F. 

The Gutheie Stripixg Device. 
In the machine shown in Fig. 222, the fabric A is placed on the 
rollers B and C, which are supported on the ends of the frame D. 




1 ^ 'e 



Fig. 222. — The Guthrie Striping DE\r[CE. 

This is one of the older types of striping machines in which the ends 
of the fabric were united like a driving belt. One of the rollers is 
driven by power or by hand while the other is turned by the fabric. 
On each side of the frame is a metal plate E which supports the scraper 



SPREADERS, DOUBLERS ASD SURFACE FIXISHERS 221 

F. This scraper is held vertically above the curved slotted plate G. 
The lever /, which is slotted in the center so that its length and posi- 
tion may be adjusted, has one end pivoted to the metal plate E and 
the other to the slotted plate G. The slots in the plate G are shown 
at H in the plan view of the machine. The fabric moves in the 
direction indicated by the arrow and the scraper F bears against the 
slotted portion of the plate G, preventing any of the coating material 
from going past it, except that which passes through the slots to the 
fabric. Therefore since all of the material entering the slots is spread 
on the fabric in the form of stripes, the thicker the plate G is made, 
the deeper the slots will be and a corresponding amount of rubber will 
be spread on the fabric. The solution to form the stripes is placed on 
the plate G back of the scraper and the surplus falls into the trough I, 
from which it may be removed and used again. 

The Laxdix Fabeic Feed. 
Fig. 223 shows an ordinary spreader equipped with a device 
for feeding the fabric. This consists of an apron having hooks at one 




Fig. 223. — The Laxdix Fabric Feed. 



end and a clamping plate at the other, and is run by a pair of sprocket 
chains, into which the hooks catch. 

In the drawing, A is the let-off, B the wind-up, and C the spread- 
ing roll, driven in the usual manner. On each side of the spreader 



222 



RUBBER MACHINERY 



is a sprocket chain D for engaging the apron to convey it through the 
machine to the wind-up. The apron is built up in the form of a pad, 
having two outer layers of canvas and a middle layer of felt. It is as 
wide as the fabric E and long enough to lap once or twice around the 
wind-up, forming a smooth cushion for the coated fabric. 

On the rear end of the apron is a narrow metal clamping plate to 
which the fabric may be quickly and smoothly attached. On its for- 
ward end is another metal plate F, curved to fit the wind-up roll. On 
each end of this plate is a hook for attaching the apron to the chains D, 
and in the center is another hook G which catches on one of a series of 
rods in the center of the roll B when the apron reaches this point. 

The operation is as follows: The forward end of the apron is 
hooked to the chains and the rear end is clamped to the fabric. The 
spreading knife is raised and the machine set in motion. When the 
rear end of the apron has passed the roll C the knife is lowered and 
spreading begins. When the plate F reaches the wind-up it is auto- 
matically disengaged from the chains ; the hook G catches one of the 
rods in the center of the roll B ; the apron and fabric are then wound 
up in the usual manner. 




Fig. 224. — The Coulter Roll Spreader. 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 223 

The Coulter Roll Spreader. 
In this calender spreader a thick rubber dongh is spread on a 
roll by a knife and the sheet thus formed is removed "hj an apron or 
sheet of adhesive-coated fabric. (See Fig. 224.) The rubber is intro- 
duced at the top and is spread over the roll A by the adjustable knife B. 
A sheet of fabric C from the roll D passes over the roll £ -and between 
A and E, where it picks up the rubber. The sheet then passes between 
rolls A, F and G and is wound up on the roll H. If desired, a second 
sheet of fabric K may be applied to the rubber as it passes the nip of 
the rolls F and G. 

YULCAXIZERS FOR CoATED FaBRICS. 

In 1882 H. W. Burr invented an interesting apparatus for vul- 
canizing coated fabrics, especially of the Gossamer type, by exposure 
to strong electric lights. In this apparatus the curing is preferably 
effected during the coating process. Referring to Fig. 225 the fabric 




B ,^^^///i\\\\ 




^^///m^ 




Fig. 225. — The Burr Electric Light Vulcanizer. 



A is supported on adjustable rollers B and C in the frames D. The 
fabric is passed through a spreader or between the rolls of a calender E, 
from which it passes over the steam heated drying table F. Above this 
table are suspended electric lights G. The rays are reflected on the 
fabric as it passes over the table. When the fabric moves horizontally, 
as is the case in the apparatus shown, transparent glass guards prevent 
incandescent particles from falling on it. In some cases the lights 
are arranged one above the other and the fabric is moved vertically up 
and down on both sides of the lights. As a rule, the best results are 
obtained by applying successive coatings of rubber, with the light act- 
ins; continuouslv. 

The Waddii^gtox Vulcanizer. 
Fig. 226 illustrates an apparatus for vulcanizing waterproofed 
fabrics in continuous lengths. The fabric A is cured by passing 
through a heated chamber B. At the top and bottom of this chamber 



224 



BUBBER MACHIXEBY 



are numerous rollers C , which may he heated or cooled as required. 
The inlet D and the outlet E are made in the form of narrow slits 
to avoid the loss of heat. The fabric is supplied from the stock roller 
F and passes into the chamber at D. It then passes up and down over 
the many rollers until it finally emerges at E and is wound up at G. 
It is found desirable, when single texture fabrics are being treated, 
to cool one or more of the rollers C nearest the outlet hy cold water 
in order to give a better finish. It is also desirable to apply the heat 
to the fabric by successive stages as it passes through the chamber. 
This is accomplished by dividing the chamber into separate compart- 
ments by transverse partitions. In these compartments the heat may be 
controlled as required or one or more of the rollers nearest the entrance 



yf///////^ 



i==£^^^^^^f^ssms^^^SQse^i 




i;ii 1 lill|llili|iMi,, j; 

iin'iinniiiiiii ,, I; 1 



h II ' <i I 



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iMMMM^^^s^^mmi^iii^^^i^^i^^^^d.-^'^ 



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Fig. 226. — The Waddixgtox Vulcaxizer. 

may be kept cool so that the faliric is prevented from becoming heated 
too soon to the same degree as the interior of the heating space. 



The Vapoe Cuke. 
The vulcanizing of goods by acid fumes, a process often used. 
is done in a vaporizing room made of clear kiln-dried white wood 
boards, the ordinary size being 7 feet wide, 7 feet high and 12 feet 
deep. This room is made with the frame on the outside, the sheathing 
being on the inside. It is put together with galvanized nails, screws 
and hinges, the steam fittings also being galvanized. This is lined 
with 14-inch asbestos board and has about 180 feet of 1-inch pipe 
placed inside of the room about six inches above the floor for heating. 
The pipe is arranged in two coils, one on each side of the room, leav- 
ing a clear space in the middle. Strips of wood ly^ inch wide. % 
inch thick and 7 feet long, with round corners, are placed crosswise 
in the room 2 inches apart and 6 inches below the ceiling. All the 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 225 



uncovered woodwork is coated with shellac. There are four small 
sliding doors, one on each side, the bottom being level with the steam 
pipes. A ventilator with a damper is placed at the rear of the room 
and as near the top as possible. The front of the room has folding 
doors the entire width of the room. The coated cloth is festooned 
from the cross bars, the bottom folds hanging about twelve inches 
from the floor. A room of this size will hold about 400 yards of fabric. 
A small china dish is placed on the pipes at each of the sliding doors, 
and in each one is poured one-eighth of an ounce of chloride o± sulphur. 
The doors are closed and the room kept tight for from 15 to 20 min- 
utes, depending upon the thickness of the goods. The ventilator and 
the small doors are then opened, and about 20 minutes allowed for 
the fumes to pass off. In the meantime clean plates are placed on 
the pipes, each plate containing an ounce of ammonia. After 20 to 
30 minutes with the ventilator opened about half the time, the goods 
may be removed. 

The Bridge Cold Cure Machine. 
The machine shown in Fig. 227 is used for cold curing, starch- 
ing and finishing. The fabric to be treated is wound on the brake 
roller A, from which it is conducted under the guide roller B and 
over a slate distributing roller revolving in the tank C containing the 
vulcanizing liquid. By means of the lever D the fabric may be raised 




Fig. 227. — The Bridge Cold Cure Machine. 



out of contact with the distributing roller. After being treated the 
fabric passes around guide rollers E and F, down an incline and under 
the steel bladed doctor G which spreads the farina or starch evenly 
over the surface of the cloth. It then passes under a second gage // 
with a smooth wooden edge, and thence over the roller / to the steam 
drying cylinder /. After being cured the fabric passes over a high 



226 



RUBBER MACHINERY 



speed brush K and then between two wooden guide rollers L to the 
wind-up roller M. The brush and wind-up roller are driven respec- 
tively by belts N and . from an overhead shaft. The shaft of the 
cone pulley P, w^hich drives the wind-up roller, has a clutch operated 
by the lever R. When the machine is used for curing only, the fabric 
does not pass under the two gages G and H nor does it come in contact 
with the brush, but passes directly from the drying cylinder to the 
wind-up roller. 

The Keemer Impregiv^atoe. 
The machine shown in Fig. 228 is for saturating fabrics by pass- 
ing them through rubber solution and afterwards squeezing the fabric 




Fig. 228. — The Kremer Impregnator. 



between two rubber rollers. Referring to the two draw^ings, A repre- 
sents one end of the machine while B is an enlarged sectional view 
showing the scrapers and rubber rollers. On the front of the frame G 
is stock roller D from which fabric E is unwound. The fabric passes 
up over roller F and down into tank G containing the rubber solu- 
tion. While passing through this tank the cloth becomes saturated 
and the surplus is scraped off by the scrapers H, and falls back into 
the tank. The fabric then passes between two rubber rollers 7 and / 
held together by spring K and adjusted by screw L. When these 
rollers are compressed, as shown in drawing B, their line of contact 
becomes a surface of considerable area and during the passage of the 
fabric between these rollers the rubber solution is pressed into the 
fibers. From rollers I and / the fabric passes between a second pair 
of rollers M and over a steam heated drying table N, only a short 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 227 

section of wliicli is shown. From this drying table the fabric is wonnd 
up at the opposite end of the machine. 

The Siveeso:^ Impeegistatoe. 
The impregnator, shown in Fig. 229, is designed especially for 
impregnating heavy fabrics. The apparatus comprises an inner impreg- 
nating tank A, adapted to receive the plastic mass of unvulcanized 
rubber compound and the fabric. Outside the tank ^ is a jacket B 
forming an air space C. Outside of this jacket is a shell D forming the 




Fig. 229. — The Siverson Impregnator. 

space E, heated by steam. The two spaces C and E are closed by 
the metal ring F, and a cover G is provided for the tank A. After 
the fabric and rubber have been placed in the tank the cover is 
secured by means of bolts H and air pressure is applied through pipe 
/ for forcing the rubber solution into the fabric. A branch "pipe / 
conducts a portion of the compressed air to the space C. This provides 
a heat-insulating medium which prevents the rubber from vulcanizing 
before the fabric is thoroughly impregnated. This process enables a 
much denser mass of rubber to be used than where no insulating medium 



228 



RUBBER MACHINERY 



is placed between the steam jacket and the tank. Heat is snpplied 
to the space E through the pipe K. A pressure of 75 pounds is 
employed in the tank A and a pressure of 45 pounds in the insulating 
space. The temperature of the steam jacket is maintained at about 
350 degrees F. 

The Destribats Impregxatok. 
Among the newer machines for use in connection with the proof- 
ing of fabrics is one invented by Destribats. The object is to remove 
the air from the fabric and coat it with rubber before comins; in 




Fig. 230. — The Destribats Impregnator. 



contact with the atmosphere. The fabric is also heated by steam at 
the same time the air is exhausted so that it is perfectly dry. 

Referring to Fig. 230, which shows a cross section looking toward 
the end of the machine, the roll of fabric A is mounted on the shaft 
B in the frame C. This has rollers D, which run on the track E in 
the shell F, which has a removable door. The air is exhausted from 
the shell by means of an ordinary vacuum pump. Surrounding the 
roll of fabric are steam pipes /, and on top of the shell is trough L 
with a long slot M and a pair of flaps X , to prevent the rubber solu- 
tion from being drawn into the shell when the air is exhausted. A 



SPREADERS, DOUBLERS AXD SURFACE FINISHERS 229 

roll of fabric which is to be impregnated is placed in the frame G 
and run into the cylinder. The end is carried around the steam pipes 
I and nnder the roller P, and then verticallv through the slot M 
into the rubber solution. The air is exhausted from the cylinder 
and the cloth is impregnated. The coated fabric then passes between 
a pair of rollers R and over a heater H, after which it is wound up 
on the roller S. 

The Rushwoeth Showee Peoofee. 
The machine shown in Fig. 231 is designed for waterproofing 
textile fabrics with parafine wax compositions made up in the form 
of slabs which melt at a temperature below that which would damage 




Fig. 231. — The Rushworth Shower Proofer. 



230 RUBBER ^LACHISERY 

the fabric. The drawing shows a transverse section of the machine. 
The frame A bears two steam heated rollers B running the full Avidth 
of the machine. Below these rollers is a cylindrical brush C and 
below this brush is a hollow convex metal plate D o\'er which the 
fabric travels. At the upper part of the frame are vertical pillars E 
carrying a rectangular frame F and cross bars G. From these bars 
are suspended two box-like casings R with tapered bases of woven 
wire. These cases contain the slabs of waterproofing compound I. 
Below the wire network is another series of wires / above the sur- 
faces of the rollers B. 

The machine has a tension device K, guide rollers L and d/ and 
drawing rollers X and 0. The cylinders B, brush C and drawing 
rollers N and are driven by gearing in the direction indicated by 
the arrows, and the surface speed of the brush is faster than that of 
the fabric. The fabric P i? mordanted in the usual manner and then 
passes over the guide rollers and between the plate D and the brush 
C. The hollow plate D and the two rollers B and the roller X are 
steam heated. Heat from steam pipes Q slowly melt the waterproofing 
material which drops from the pending wires on the heated cylinders 
B Avhich transfer it to the brush C. This brush spreads it evenly 
over the surface of the cloth. End plates R confine the material to 
the cylinders B and after the fabric has been passed through the 
machine the steam is turned off and cold water is passed through the 
pipes to cool the machine. 

The Taltee Showee Proofer. 

The machine shoAvn in Fig. 232 is designed for the purpose of 
coating both sides of the fabric in one operation with waterproofing 
material. The material in the form of solid bars has a wax-like con- 
sistency and is applied to the fabric by friction which melts the wax 
just fast enough to allow an even coat to be spread. Between the 
frames A and 5 is a roller C which is mounted diagonally so that 
the fabric D enters the machine at a right angle. The fabric passes 
from this diagonal roller over an idler roller E and then between the 
roller F and the upper edge of the bar G of waterproofing material. 
The fabric then passes around rollers H and I in the frame A and 
under the idler roller ./ and between the roller K and the lower edge 
of the bar G thus coating both sides of the fabric in one operation. 
From the roller K the fabric passes between a pair of heated calender 
rollers L and M. The spreading rollers F and K move toward each 
other as the bar of waterproofing material wears away, as they are 



i 



SPREADERS, DOUBLERS AXD SURFACE FINISHERS 231 



H 



u 



^ 









C 



7^ 





Fig. 232. — The Falter Shower Proofer. 

moimted in movable bearing blocks which are acljnsted by a system 
of leyers and weights. These are so arranged that the pressure of 
the rollers against the fabric always remains the same, resulting in 
spreading a uniform coat of material on the cloth. 

SoLVEJs^T Recovery. 
The recovery of the solvent, which is bv no means unimportant, 
is accomplished in most of the large spreading plants. Of the pro- 
cesses used the following are the most interesting: 




Fig. 233. — The Weber-Frankenburg Recovery Apparatus. 



2S'2 BUBBER MArHIXBBY 

The Webek-FraxkexbuPvG Recovery Apparatus. 
Fig. 233 illustrates a vertical section aud a side view in which 
A is a steam heated drum surrounded bv a cylinder B, with a space 
C between the two parts. In the outer cylinder is an opening D to 
admit the fabric B, and an opening F through which it passes out 
over a giiide roller H. The outer cylinder B serves as a condenser 
and it may be cooled by the atmosphere or by a water jacket J/ sur- 
rotmding it. A shutter H is placed at the entrance B to prevent a 
current of air being carried through. The fabric passes around the 
steam heated dram A and the vapors are condensed upon the cold 
walls of the cylinder B, and flow down the sides of the cylinder, 
accimiulating at the bottom. At its lowest point the cylinder is pro- 
vided with a drain pipe I, through which the liquid solvent is con- 
ducted to a tank /. In order to minimize fire risks the drain pipe 
is provided with a siphon bend K and the pipe tei-minates in a water 
seal L at the bottom of the tank •/. The solvent, being lighter than 
water, rises to the top and may be drained olf as desired. 

The Vixcext Appaeates. 
In the apparatus, illustrated in Tio-. 23i. the proofed fabric is 

It 




Fig. 234. — The Vixcext Apparatus. 



continuously imroUed imder a closed hood in which the volatile pro- 
ducts are vaporized and carried off by a current of heated air. In 



SPREADERS, DOUBLE RS AND SURFACE FINISHERS 233 

the draAving A represents the knife of the spreading machine and 
B the spreading roller. The fabric passes over the drying table C 
and is wound up on the roller D. The drying table is covered with 
a large hood E to prevent the escape of vapor. To insure this, one 
end of the hood terminates against the knife A and the other against the 
roller B. The joints are kept tight by means of a packing of felt 
or other substance. The two rollers F, between which the fabric 
passes to the take-up roller, are also sealed by felt packing. Inside 
the hood are a number of curved plates G intended to obstruct the 
air current in case the joints w^ere not tight. The solvent vapors 
leave the hood at H and pass down into I. This device comprises 
two separate parts in which the solvents pass in opposite directions 
and permits the condensation of parts of the vapors and reheats the 
cold air used for condensation. The vapors then pass through a con- 
denser / where they are further purified and condensed. At the 
outlet of the last condenser K, the purified cold air passes back into 
the second compartment of the exchanger I where its temperature 
rises. It is then forced by a fan L into a reheater M fed by hot 
water from condensed steam from the drying table C. The air from 
this reheater may be returned directly to the hood through a pipe N 
if the temperature is sufiiciently high, or it may be delivered to a 
second heater through the pipe P. A tube Q is provided for the 
introduction of free air if desired. Another tube R is supplied for 
the escape of air by the opening of a two-way cock. The installation 
also comprises measuring apparatus, valves, etc., and a pipe S for 
isolating the heater 0. It will be understood that all uncondensed 




Fig. 235. — The Heinzerling Apparatus. 



234' 



RUBBER MACHINERY 



vapors are retiirnecl to the hood bv the confined air, thus resulting in 
a theoretical total recovery of the solvents. The soh'ents recovered 
on the first round pass off through pipes T and U into a suitable 
closed vessel, while the uncondensed vapors are returned to the heaters 

and coolers. 



The IIeixzekli]n"g Appaeatus. 
In the solvent recovery apparatus, shown in Fig. 235, air is com- 
pressed by a pump A, which forces it into a coil of pipes in a con- 
densino' chamber B, cooled bv water enteriup- at C and leavino: the 
condenser at D. The compressed and cooled air then passes through 
tubes in the condensing chambers E and the vapors which condense 
are collected in receptacles F. The compressed air next passes through 
the pipe G into a cylinder H, where it expands and drives the piston 
I connected by a rod M with the compressing piston J in the cylin- 
der A. A still further fall of temperature is thus produced, and the 
vapor condensed thereby collects in a receiver K. The expanded and 
cool air then passes back through the pipe N to the condensers E where 
it cools the vapor and air which has collected therein. The air finally 
escapes through tlie pipe L. 



D 






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B 






va 



3 



\^^sr 



'^f 



gza 



D 

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Id 
£ 



Fig. 236. — The Spenle Solvent Recovery Machine. 



SPREADERS, DOUBLERS AND SURFACE FINISHERS 235 

The Spe^sLe Solvent Kecoveey Machine. 
The apparatus shown in Fig. 236 recovers the solvents during 
the process of drying. The fabric A passes directly from the spread- 
ing machine into the vertical drying chamber B which is heated by 
steam chests or pipes C. It passes around guide rollers D in such a 
manner that the coated side of the fabric does not come in contact 
with the rollers until sufficiently dried to prevent sticking. The fabric 
passes out at the lower end of the dryer and to a wind-up roller in the 
usual manner. The walls of the drying chamber B are cooled by 
water pipes, while the top of the dryer is heated to prevent con- 
densation directly above the drying fabric. The condensed solvent 
collects on the side walls of the dryer and runs do^\m into the troughs 
E, from which points it is drained off and collected for reuse. 




Fig. 237. — The Spenle Solvent Recovery Machine. 

Another solvent recovery apparatus designed by Spenle is shown 
in Fig. 237 applied to a horizontal dryer. An outlet at the upper 
end of the drying chamber A is connected with a suction fan B. 
Adjacent to the openings where the fabric enters and leaves the cham- 
ber are pipes C and D which direct the air on the fabric E as the 
latter enters and leaves the chamber A. To accomplish this the pipes 
C and D have slots or ports in their lower sides, and the air received 



by the fan is circulated back into the drying chamber. The suction 
and delivery connections of the fan are so proportioned that the air 
flowing over the cooling pipes F travels at low speed to insure perfect 
condensation of the vapors. Also, the jets of air from the pipes C 
and D are sufficienth' strong to prevent the escape of vapor. 



236 



RUBBER MACHIXERY 



The Boecler Soevext Recovery Apparatus. 
Fig. 2 38 shows a side elevation and a cross-section of the device 
in connection with an ordinary horizontal spreader. The hood A 




Fig. 238. — The Boecler Sol^-ent Recovery Apparatus. 

completely snrrounds the table B of the spreader, dividing it into an 
npper and lower compartment. The snpports C of the table project 
through the hood, and at these points the hood is flanged and made 




Fig. 239. — Exhaust Hood for Solvent \\\pors. 



SPREADERS, DOUBLERS AXD SURFACE FINISHERS 237 

air-tioiiL. The upper compartment has transparent windows D, which 
permit the operation to be observed without opening the hood. The 
sides of the lower compartment are inclined so that the condensed 
solvents will flow to the exit E. These lower walls are water-jacketed 
at F, the cooling water entering at G and flowing out at H and /. The 
vapors which arise from the spreader table B cannot escape on account 
of the hood. They therefore partly condense and flow down the sides. 
escaping through passages / and K into the lower compartment. 

Exhaust Hood for Solvejs^t Vapors. 
Fig. 239 shows a horizontal spreader with a large funnel-shaped 
device suspended directly over the drying table and connected by a 
flue or pipe with an exhaust fan. When the proofed fabric is started 
across the drying table the vapors rise and the fan creates a steady 
draught which causes them to pass upward into the fumiel, to the 
solvent recovery apparatus. This apparatus may be any of the types 
described above for receiving the vapors and condensing them. 



CHAPTER XIY. 

CEMEXT AXD SOLUTIOX MACHI:N^ERY. 

WHILE the amount of rubber cement produced is very large, 
there is no complicated machinery used. The churn mixer 
or muddler is the principal appliance and its office is to put 
massed or compounded rubber into solution with naphtha. 

A common design for a cement mixer is a cylindrical tank with 
a bolted-on top, and a hand-hole for introducing the material. On the 
front near the bottom is a gate vah^e for drawing out the cement. The 
lower end of a vertical shaft, provided with stirring paddles, rests 
in a step bearing in the center of the tank at the bottom. The upper 
end is journaled in the cover and driven by bevel gears and a cross 
shaft. The tight and loose pulleys on this shaft are driven from an 
overhead counter-shaft. 

In cement that is made for spreader work or for outside trades. 
the following procedure is followed. The rubber is washed and dried 
in the usual manner. It is then masticated or massed and put into 
churns or muddlers, or a dough machine, or in a masticator with the 
solvent. Erom there, if necessary, it goes through hydraulic strainers 
and then it is ready for use. 

Almost all manufacturers of rubber goods are makers of cement 
for their own use. Where small quantities of cement for special com- 
pounds are to be made large sheet iron tubes are usually employed, the 
mixed sheet being first well softened by heat, and then cut up into a 
sufficient quantity of whatever solvent is to be used. A rapid stirring 
greatly facilitates the action of the solvent, but good cement needs 
several hours of digestion before it is fit for use. Where larger quan- 
tities are to be made, iron tubs are partly filled with the solvent, which 
is, in most cases naphtha, and the rubber is run through the "refining 
mill,'' coming out in thin sheets, v/hich are cut off and plunged, warm 
as they are, into the tub of liquid, the whole mass being meanwhile 
rapidly stirred. In large factories where great quantities of cement 
are used, machinery is employed to do the stirring. 

Cemext Muddeee. 

The machine ilhistrated in Eig. 24-0 is the ordinary muddler and 
is used for mixing cement in large quantities. It is a cylinder mounted 



CEMENT AND SOLUTION MACHINERY 



239 




Fig. 240. — Cement Muddler. 




Fig. 241. — The Bridge Dough jMill. 



240 



RUBBER MACHINERY 



on concrete foundation A supporting frames B in which is journaled 
the main shaft C. This is driven by spur gear D from a belt driven 
pinion shaft E. The cylinder F revolves with the main shaft C at 
the rate of 15 R, P. M. and has an opening for filling at G and a 
gate valve H for discharging. A variety of simple stirring devices 
are used taking the form usually of longitudinal blades attached to 
the sides of the cylinder. 

The Bridge Dough Miee. 
The dough mixing mill shown in Fig. 241 is of the same general 
design as the ordinary rubber grinding and mixing machine but it 
has special adjustable attachments to facilitate and improve the mix- 
ing. The rolls A and B are connected together by friction gears C, 
which revolve the adjustable front roll A at a surface speed less than 
that of the drive roll B. The latter is driven by the large spur gear 
D that meshes with a driving pinion on the shaft of the friction 
clutch E. Between the rolls are two gaiides F which keep the dough 
from the roll ends. Above the roll 5 is an adjustable doctor G, which 
scrapes the dough from the rolls. 




Fig. 242.— The Bertram Dough Mill. 



The '^Univeesae" SoErTioN Mixer. 

Fig. 243 illustrates the Werner & Pfleiderer kneading and mixing 

machine. The view on the left shows the machine closed, while the 

right shows it open for discharging. The mixing trough is supported 

on two side frames with bearings for the driving shaft. On the outer 



CEMENT AND SOLUTION MACHINERY 



241 




Fig. 243. — "Universal" Solution Mixer. 

end of the main shaft is keyed a pinion which engages a spnr gear 
keyed to the end of one blade shaft. This extends throngh the trongh, 
which swings upon it when the machine is to be emptied. The other 
blade shaft is parallel to the first but runs in bearings fastened to 
the trough itself and driven from the first shaft by a spur gear and 
pinion. The two shafts with their steel blades turn toward each 




Fig. 244. — The Befstorff Solution Mixer. 



242 



RUBBER MAC Ely FRY 



other in the trough at the same rate of speed. The trough is jacketed 
for heating by steam or cooling with water. Stuffing boxes for the 
blade shafts are arranged to prevent cement leakages and to keep lubri- 
cating oil from entering the trough. The machine is belt driven and 
has a two-speed gear for driving the blades at low speed when the 
mass is heavy and at a high speed to finish off quickly wlien the mass 
has been reduced sufficiently. To empty the machine the trough is 
turned forward by a hand crank and the hinged top, which is counter- 
balanced at the rear, opens by the same motion. A hinged lip guides 
the solution into the receptacle. These machines are made in various 
sizes from 1 to 200 gallons capacity. 

Change Cax Cemext Mixer. 
In the machine shown in Tig. 245 a can containing the finished 
cement is taken from the machine and another one substituted. The 



\ 


k 




A 


m^ 


-/r 


(S "i^MAAJ^^M 


WmwKW^^:::^ 


€ 


^^\ 


r . 


m 


i 


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m 


F 




■ 

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SIK5H 


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It 


-D 


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Fig.' 245. — Change Can Cement ;Mixer. 



CEMENT AND SOLUTION MACHINERY 



243 



base of the machine has a step bearing in which revolves a short ver- 
tical shaft snpporting the platform. This is really a large bevel 
gear A, on which the can B is placed. It is driven by a bevel gear C 
mounted on shaft D. This is driven b}^ a spur gear and pinion from 
the driving shaft, revolved by belt pulley E from an overhead counter- 
shaft. F is the cover to which is attached bevel gear G and also 
four stirring blades H. The bevel gear G is keyed to a short shaft 
which revolves in a bearing that forms a part of the sliding head /. 
To operate the machine, can B, containing the rubber and solvent, is 
placed in position and sliding head I and. cover F, with its bevel gear 
and stirring blades H, is lowered into the can by handwheel K oper- 
ating a rack and pinion. The bevel gear G meshes with gear C, and 
when poAver is applied the can is driven in one direction and the stir- 
ring blades in another. The sliding-head / has a counterweight so 
that the cover and blades are easily raised when the operation is 
finished. 

TwiT^ Solution Chueks. 
Fig. 246 illustrates the Ross twin solution mixer, of the over- 
driven beater type. Two tanks are supported a short distance above 
the floor so that the solution ca.n be drawn off through the sliding gate 




Fig. 246. — Twin Solution Churns. 



244 



RUBBER MACHINERY 



valves. The vertical shafts are journaled in bearings centrally located 
in the framework bolted to the tanks. These have stirrino; blades at 
their lower ends and are driven by bevel gears keyed to the top ends, 
and are. in tnrn, driven by pinions keyed to the horizontal shaft. This 
is driven by belt pnlleys and has two claw clutches so that each machine 
can be started and stopped independently. The tanks are open at the 
top and have steam connections. 



The Teoestek Soeutio^s^ Chue^^. 
Fig. 247 shows a German type of churn. It consists of a cylin- 
drical tank supported on an open base. A cover is bolted to the tank 

Li 




Fig. 247. 



-The Troester Solution Churn. 



and has a handhole A, through which the rubber and solvent are 
introduced. The vertical shaft B carries stirring paddles C which 
pass between blades L attached to the sides of the tank. The lower 
end rests in a step bearing in the center of the tank at the bottom. 
This bearing is lubricated by grease cup D. The upper end of the 
shaft is journaled in the cover and driven by a bevel gear E , engag- 
ing a bevel pinion F keyed to the cross shaft G. This shaft has bear- 
ings H bolted to the cover and is driven by belt pulley / from an over- 



CEMEXT AND SOLUTION MACHINERY 



245 



head coiiiitersliaft. The soliition is drawn off through the valve J, 
and the vapor is conducted by pipe K to an open air vent or to a solvent 
recovery apparatus. These churns are made with a capacity of 13 to 
65 gallons. 

The Bridge Solution Paxs. 
Fig. 248 shows a beater type on the right and on the left 
is an under-driven machine. The base A supports in two bearings the 
main driving shaft, driven by pulley B, from an overhead counter- 



M /\ L 



¥^^ 




Fig. 248. — The Bridge Solution Pans. 

shaft. On the end of this shaft is keyed a bevel gear C which drives 
a larger bevel gear I) , keyed to the vertical shaft E, which is journaled 
in the top frame at F . Two mixing cones roll on the bottom of the 
pan and are held in position by two guards suspended from the top 
frame. The pan B, revolves with the large gear E and the dough is 
thoroughly mixed by the rolling cones. 

In the drawing on the right, tank H is supported above the floor 
so that the solution can be drav^n off through gate valve /. The tank 
has a vertical shaft resting in step bearing at the bottom and sup- 
ported at its upper end by the central bearing J , bolted to the cover. 
The beater blades are rigidly attached to this shaft, which is driven by 
a bevel gear K meshing with a pinion L keyed to the horizontal driv- 
ing shaft M. This is driven by pulleys i\^ from an overhead counter- 
shaft. The cover has a handhole , through which the machine is filled. 



246 



BUBBEB MACHIXEBY 



The Dee^t Solutiox Mixee. 
The Drew mixer. Fig. 249. consists of cylindrical tank A, cylinder 
B. and a reciprocating plunger C, which draws the rubber solution 
through a sieve IK The softened rubber and solvent are put in the 
reservoir A and the up stroke of the plunger draws the solution into 
the cylinder. The valves in the plunger open when it descends and 
the solution in the lower end of the cylinder passes to the upper end. 
The next up-stroke draws a new charge through the sieve and delivers 
the first charge through the pipe E and valve F back into the reservoir. 
A continual circulation is maintained throtio'h the sieve imtil the con- 




Jr- 



Fig. 249. — The Drew Solutiox ^.Iixer. 



tents of the tank are thoroughly mixed. By turning the three-way 
valve Fj samples of the solution may be taken through the pipe G 
during the operation. The tank is drained through pipe H. 

Simple SoLrxiox Steaixee. 

One of the simplest forms of solution strainer is shown in Tig. 

250. It consists of a single roller fixed in the bottom of a wooden 

hopper, against which press adjustable slides, fitted with leather strips. 

The roller is moimted on cast iron standards and driven bv a belt 



CEMENT AXD SOLUTION MACHINERY 



247 




Fig. 250. — Simple Form of Solution Strainer. 

pulley. Provision is made to prevent the oil used for lubrication of the 
bearings from getting inside the hopper. The machine is sufficiently 
high to admit of a good sized tank being placed underneath. 

ScEEAV Type Steaiis^ee. 
Fig. 251 shows two views of Bridge's solution strainer, of the 
screw type. It consists of an accurately bored cast iron cylinder, 
about sixteen inches in diameter and eighteen inches deep, with a 
removable perforated bottom. The cylinder is mounted on strong 
standards of sufficient height to admit a can beneath. Over the per- 
forated plate, fine removable copper gauze discs are fitted. After 
the cylinder has been charged, the cement is forced through the strainer 
by a tight fitting plunger and screw driven by belt and worm gearing. 
When the plunger has reached the bottom the machine is automatically 
stopped and the plunger quickly lifted by a handwheel. 

TIydeaulic Steaixee. 
Fig. 252 shows Bridge's hydraulic solution strainer. It is sup- 
ported at a distance above the floor so that the solution is strained 
directly into a receptacle. The hydraulic cylinder A is mounted on 
the main body of the machine and the lower end of the piston B is 
adapted to fit the cylinder C in which the solution is placed. This 
cham.ber has a removable, perforated bottom plate, over which fine 
copper gauze discs are fitted. After the cylinder has been charged, 
the piston, operated by hydraulic pressure, forces the solution through 
the strainer. A three-way valve, operated by a handwheel D, controls 



248 



RUBBER MACHISERY 




Fig. 251. — Screw Type Strainer. 

the movement of the ram. The chamber C is provided with steam con- 
nections for heating the solution. 

Machine for Filling Tubes. 
Fig. 253 is a side elevation and Tig. 254 a plan view of Brett's 
machine for filling cement tnbes. A is the reservoir and B the pump 
for filling the tubes. C is a pipe connecting the reservoir A with the 
end of the pump cylinder. D is a valve fitted in the pipe C , and E 
is a small sliding valve at the top of pipe C, controlled by an external 
handle F. H is the piston on the end of the piston rod I, and / is the 
piston valve, K m sl nozzle upon which is placed the collapsible tube L. 
The nozzle is screwed to a projection on the sleeve M^ which slides 
on the front end of the cylinder B, which communicates with the 
nozzle through a hole, when the sleeve is placed in such a position that 
the nozzle comes opposite the hole. By sliding the sleeve upon the 
end of the cylinder it can be brought opposite a by-pass in the under 



CEMEXT AND SOLUTION 21 AC NINE BY 



249 



side of the cylinder, to allow the solution to escape. A slide valve N 
controls the flow of the solution from the cylinder B into the tube L. 
The solution is stirred in the tank A by the arms 0^ mounted upon 
a vertical spindle P and rotated through bevel gears Q operated by a 
handle B. Stationary arms S are attached to the sides of the tank, 
and the arms revolve between them. 

In filling the tubes the valves D and E are opened and the lever T is 
pressed forward, drawing a supply of solution from the reservoir into the 
cylinder B. The piston is then pulled back and the solution passes 
through the piston valve / and fills the cylinder. When the piston 
is again pressed forward, and valve N being held closed by a spring U, 
the solution offers resistance to the forward motion of the piston. This 
extra pressure moves the links V, ^Y, X and Y and pushes the slid- 
ing valve N inward so that the passages are uncovered. The solution 
now passes through nozzle K into the tube L^ while the overflow escapes 
through the by-pass. The operator releases the handle and the spring 
U closes the valve N, so that the tube may be removed without loss of 
solution. 




Fig. 252. — Hydraulic Strainer. 



250 



BUBBER MACEIXEBY 




Fig. 253. — Side .View of the Brett IMachixe for Fillixg Tubes. 

It is aclniitted in all factories where the article is used that cement 
is a dangerous servant. In most well regulated places the mixing 
and stirring of cement is done in a fireproof building, known as the 
cement-house. This mav be near the factorv to receive the benefit of 



l^s 



V 



(J 



r 







^ 


r 


^\ 








r 


\ 


s 


// 



■A 



\^L 



-A 



I 



Fig. 254. — Plax \ iew of the Brett Machixe. 



CEMENT AND SOLUTION MACHINERY 



251 



the steam power, and vet be so distant and protected as to be harmless 
either from sudden explosion, or fire from any other cause. 

The Bowser Cement Can. 
The rubber cement can sho^\m in Fig. 255 is of the portable type, 
comprising a heavy metal tank to which is attached a brass suction 
pump. It is designed for distributing cement to the various depart- 
ments of a rubber factory. The pump will discharge at one stroke, 
an accurate pint, half -pint or quarter-pint. It has an anti-drip nozzle 
with a lever shut-off, which cuts off the flow when pumping ceases and 




Fig. 255. — The Bowser Cement Can. 



prevents deterioration of the cement. The cover has four open lugs in 
which fit the swinging bolts attached to the can, and is tightened by 
four winged nuts. A hand hole and a vent are also provided in the 
cover. 

The Bowser Ce^/ent Storage Tank. 
The tank shown in Fig. 256 is for storing and measuring rubber 
■cement. It is a rectangular metal tank, fitted with a combination suc- 
tion and force pump. This will discharge at one stroke a gallon, half- 
gallon, quart or pint at the will of the operator. The tank has a 
flanged connection containing an automatic vent valve, which terminates 
in an air vent protector at some point outside of the building. The tank 



252 



RUBBER MAC HIS FRY 



lias a sloping bottom which causes the liquid to llow into a pocket con- 
taining the foot valve of the pump, thus permitting all of the cement 
to be drawn off. A hand hole is placed in the front near the bottom^ 




Fig. 256. — The Bowser Cemext Storage Taxk. 

so that it may be cleaned out. Tanks having a capacity of four bar- 
rels or more have two clean- out openings. 



Batteey Storage Outfit. 
Fig. 257 shows a battery of six self -measuring cement storage 
tanks, equipped with a barrel cradle, track and chain-hoists for stor- 
ing and handling cement in large quantities. The barrel is placed 
on the cradle, raised into position by means of the hoist, then rolled into 
place over any tank, and the contents transferred to the tank by gravity. 
Splashing and waste are prevented by the barrel dash. This arrange- 
ment makes unnecessary the use of a transfer pump. The whole equip- 
ment is air-tight. The action of the pumps in drawing the cement 
frona the bottom of the tanks tends to keep the contents agitated, thus 
maintaining a uniform consistency. 



CEMENT AND SOLUTION MACHINERY 



253 




Fig. 257. — Battery Storage Outfit. 
I^APHTHA Storage. 
The Bowser equipment in Fig. 258 consists of an underground 
naphtha tank and fill pipe running to a point accessible to the supply. 




Fig. 258. — Naphtha Tank and Pump. 

A hand pump, placed inside the building, accurately measures gallons, 
half gallons, quarts and pints at a stroke. It can be adjusted to deliver 
any intermediate quantity. A gage on the tank indicates the amount 
remaining in the tank and is a check on the delivery. 



CHAPTER XV. 

EXTEACTIOX OF RUBBEK AXD GUTTA FROM SHRUBS, 
VIXES, ROOTS AXD LEAVES. 

THE extraction of rubber from Giiayiile shrubs, vines and roots 
and gntta from leaves, has been of great interest and importance. 

It lias been most successfully done near the source of supply, 
although Guayule shrub sent to the United States and Germany has 
been successfully extracted. It is only when the rubljer appears in 
the form of rubber in a plant and not in the form of latex, however, 
that this extraction from dried plants has been even remotely successful. 

Certain types of rubber producers, namely, African vines and 
Mexican shrubs, are susceptible to the extraction of the rubber con- 
tained in them by mechanical means. It is only in Mexico, in con- 
nection with the Guayule plant, that this has been done on a large 
scale. 

GuAYrLE. 

The ordinary process for extracting Guayule from the shrub is 
as follows : The bales from the field are opened and the shrub fed 
by hand to the crushers, small end first, the crushers being flooded 
with water. The crushed shrub then goes to a pebble mill, the charge 
being 6 bushels to 150 gallons of water. From there the pulverized 
mass is floated to skimming tanks. Here the rubber and light bark 
float and the heavy wood fiber sinks. The rubber and bark is then 
floated off to another tank and into a revolving screen, where the 
dirty water is got rid of. Then it goes to a compression tank where 
the bark is settled; then to an ordinary tub washer and finally to a 
two-roll rubber washer — after which it is dried. 

There are other systems; for example, extracting the rubber by 
alkaline baths or by solvents. There are also many types of crushers, 
disintegrators and extractors. 

Guayule Sheeddee. 

The Williams machine for cutting and shredding Guayule shrub 

is illustrated in Fig. 259. The shrub is thrown on a traveling feeder 

A, which carries it along until it comes in contact with the lower side 

of the presser B. This is in the form of a traveling apron driven 



EXTRACTIOX OF RUBBER AXD GUTTA 



25; 



by a sprocket chain passing over sprockets C and D. The sprocket 
wheel D is adjustable to accommodate the varying bulk of the shrub. 
The discharge end of the apron B rises as the material passes through, 
and this raises the feed roller E by the chain F. This feed roller 
forces the shrub over the stationary cutting knife G. The loosely 
jointed beaters H are placed in rows on the shaft. They are extended 
by centrifugal force and cut off the shrub according to the speed of 
the feed rollers and the apron B. If metal or other forei^'u material 




Fig. 259. — Guayule Shredder. 

is fed in with the shrub the machine stops automatically. The cut 
shrub falls on the perforated iron screen I, where the work of pulveriz- 
ing is finished. The fine material falls through the screen and is taken 
up by the fan ./ and forced through the pipe K into the dust separator 
L. Here the dust is separated from the shrub containing the gum. 



Rotary Cutter. 
The Abbe rotary cutter, shown in Fig. 260, cuts roots, vines or 
shrubs to any size, before feeding to the pulverizer. The machine con- 
sists of a cylindrical casing A in which five knives B revolve against 
six stationary knives C set inside the casing, three on each side. The 
knives are set at a slight angle, giving a shearing action. The shrub 
is fed into the hopper D^ and cut by the knives which carry it over the 
perforated bottom plate E. If fine enough it falls through, otherwise 
it is carried up and recut until sufficiently reduced to pass through the 
perforations. The fineness depends wholly on the size of the holes in 
the plate. The knives are adjustable and the plate E is removable. 



256 



BUBBEB MACHIXEBY 




Fig. 260. — Rotary Cutter. 



Tpie Abbe Pebble Mill. 

Pebble mills grind by friction, produced by a great number of 
flint pebbles or porcelain balls tumbling and rolling inside a revolving 
cylinder. 

Fig. 261 shows a pebble mill for reducing Guayule. It is an 
iron cylinder set on trunions. revolved by spur gears from a belt 
pulley, and has steam or air connections for grinding under pres- 
sure. The cylinder is porcelain lined and has a flanged manhole to 
which a tight cover or discharging screens may be bolted. The material 
is placed in the cylinder with the pebbles and the cover bolted on. 



EXTRACTION OF RUBBER AND GUTTA 



257 




Fig. 261.— The Abbe Pebble Mill. 




Fig. 262. — The De La Corte Crusher, 



258 



RUBBER MACHIXERY 



The mil] is revolved until the material is sufficiently reduced, when 
it is discharged through the screen. 

The De La Coete Ce usher. 
Fig. 262 shows four cylinders A, B, C and D, each of which 
contains a spiral feeder. The shruh is first broken up in short pieces 
and fed into one end of cylinder A from a hopper E and conveyed 
to the opposite end where it passes between a set of grinding discs. 
These partially crush it, after which it falls into the end of cylinder B 
and is conveyed to the opposite end, where it passes between another 
set of discs. This operation is repeated in C and the pulverized shrub, 
having; reached the grinding end of cvlinder D, is discharo;ed throuoii 
the opening F. The surface of the grinding discs vary from coarse in 
the first set to fine in the last. The final cylinder D is heated to assist 
in massing the particles of rubber wood fiber. By the time the material 
reaches the outlet F the wood fiber has been thoroughlv oround and 
the rubber is then separated from it by washing. A means is provided 
for adjusting the distance between the grinding discs so that any 
desired pressure may be exerted. 



The Beidge Gijayule Ceushees. 
The drawings A and B in Fig. 263 show two types of machines 
for extracting rubber from Guayule and similar shrubs. In A the 




Fig. 263. — The Bridge Guayule Crushers. 

shrub is delivered to the rolls through the chute D by an endless chain 
of elevator buckets in a casing C. The shrub passes between the cor- 
rugated rolls E E, F F and G G, which crush and disintegTate the 
woody fiber. A stream of hot water is played over it and amalgamates 



EXTBACTIOK OF RUBBER AND GUTTA 



259 



the rubber while the waste is washed away. The scrapers H prevent 
the rubber from sticking; to the rolls. To send the shrub through the 
machine a second time, a hopper I is placed to catch it as it leaves 
the rolls G and the moving buckets convey it again to the top of the 
machine. 

In the second machine, B^ the crushing is done by a pair of plates. 
The plate / is stationary in the frame L with the front end higher 
than the back, while the plate K is level and suspended by two swing- 
ing supports 21 pivoted to the upper part of the frame. The forw^ard 
end of the plate is attached to a connecting rod pivoted on a crank N. 
When the latter is turned by the driving pulley 0, the plate K is 
reciprocated horizontally and the shrub is crushed between the plates. 
The lower plate has sides P to retain the material as it is fed from 
the hopper Q, and it is ground finer and finer as it approaches the 
rear end of the machine until it passes out into a receiver under the 
chute ^S'. The plates are chambered for steam and air is blown between 
them to remove the light bark and wood fibers. 

The Laweexce Extractoe. 

In Fig. 264, crushed Guayule shrub is delivered from a chute D 

to a tank A containing boiling w^ater, heated by steam coils B^ and 

agitated by steam from the pipe C. It is boiled for half an hour 

and then drained off through the outlet pipes B and F. These pipes 




Fig. 264. — The Lawrence Extractor. 



260 



RUBBER MACHINERY 



are fitted with horizontal, perforated tubes G, through which the mix- 
ture falls on a moving apron H. The water drains off through the 
apron into a trough I, while the shrub particles are carried along to 
the separator J. A scraper K and a sprinkler L serve to detach any 
particles which adhere to the apron. 

The separator is covered with a band of thick rubber belting M 
slightly roughened on its outer surface. An apron A of similar mater- 
ial surrounds a portion of the drum and is drawn against it by turn 
buckles 0. The Y-shaped upper end of the apron forms a hopper 
into which the fiber falls from the screen. When the drum is rotated 
the shrub is drawn between the belts with a rubbing and rolling motion. 
The particles of rubber unite and emerge at the lower end of the 
apron A in worm-like rolls. The fiber also leaves the drum at this 
point and falls with the rubber upon a conveyor and strainer P and 
is washed away by the sprinkler Q, while the rubber is carried along 
and deposited in the washing tank R. 

The Lawrejn^ce Guayule Washek. 
Guayule shrub is soaked in water for several hours and then cut 
into small pieces. These are mixed with about ten times their weight 




Fig. 265. — The Lawrence Guayule Washer. 



of water and the mixture placed in the beater tank A. (See Tig. 265.) 
From the beater the rubber is run off into the tank B, where it remains 
suspended in the water. The light bark rises to the surface and the 
wood pulp settles to the bottom. The tank has steam coils, and by 
raising the temperature of the water its specific gravitj^ is so changed 
that the rubber settles toward the bottom. The floating waste matter 
is blown bv an air nozzle C into the trou^^h D, which conducts it away. 



EXTRACTION OF RUBBER AND GUTTA 



261 



The rubber and water, with the heavier refuse, is then drained off 
into the tank E, where the rubber rests on a screen F, hinged at G. 
The water drains into the tank and the screen is lifted by the pulley 
H^ discharging the rubber and wood particles into the tank I contain- 
ing water at a normal temperature. The fiber sinks to the bottom and 
the rubber remains suspended in the water. Common salt is then 
thrown into the tank to increase the specific gravity of the water, 
causing the rubber to rise to the surface, where it is carried away on 
a swinging screen / suspended from an overhead track K, The tank 
/ is provided with coils which are connected with steam and cold 
water supply for regulating the temperature. 

The Laweeistce Exteactoe. — -(By Solvents.) 
Fig. 266 shows an apparatus for extracting Guayule by solvents. 
The shrub is first crushed and placed in a basket-like cage A which 




Fig. 266. — The Lawrence Extractor. (By Solvents), 



rests upon trunnions B supported on the track C. This has a pres- 
sure gage E, thermometer F and inlet and outlet steam pipes. After 
the cage is filled it is tilted horizontally and pushed into the steam 
jacketed cylinder D. The door G is then closed and the valve H 
opened and naphtha is forced into the drum D hj a pump J. (See 
Fig. 267.) The valve H is then closed and steam admitted to the 
jacket. The extractor is kept at 60 pounds pressure for four hours, 
then the solution is drawn through the pipe K into a steam jacketed 
evaporator L. The naphtha vapor is condensed in the coil M and 
flows into a supply tank N, to be pumped again into the cylinder D. 
The bulk of the naphtha, or other solvent used, is driven off by 
the heat of the evaporator L until the solution begins to thicken. Then 



262 



RUBBER MACHINERY 



the discharge valve is opened and the sohition passes into the 
steam jacketed tank P containing a hot alkaline solntion, Avhich is 
admitted through the pipe Q. This separates the resin and naphtha 
from the rubber, which floats as the solution cools. This is hastened 




Fig. 267. — The Lawrence Extractor. (By Solvents). 

by the introduction of cold water through the pipe Pi, after which the 
rubber is skimmed off and subjected to repeated washings with hot 
and cold water in the tank S. Under this treatment it assumes a 
dough-like consistency so that it is easily rolled into sheets between 
the rolls T. 




Fig. 268. — The Ephraim Guayule Separator. 



EXTRACTION OF RUBBER AND GUTTA 



263 



The Epheaim Guayule Sepaeatok. 

The process illustrated in Fig. 268 consists in passing the Gnayule 
shrub through a rotating cylinder with internal teeth which tear it 
to pieces. The second step is the separation of the rubber from the 
ground material bv washing and finally skimming off the floating 
rubber. 

The shrub is placed in the drum A, which is rotated by the belt 
pulley C and the gears B. The internal surface of the drum is studded 
with triangular teeth D^ which tear the shrub as the drum revolves 
and at the same time steam is admitted to the drum through the 
pipe E. When the mass is finely divided it is discharged through 
the hose F into the open trough G. Water is admitted to the trough 
through the pipe H and the heavier particles sink to the bottom and 
fall into the trough /, while the rubber, which floats on the surface, 
is skimmed off into an adjustable sluice-way /. . 




Fig. 259. — The Bridge Crusher and Extractor. 



264 



RUBBER MACHIXERY 



The Bridge Ceushee axd Exteactor. 

Fig. 269 shows an apparatus for crushing shrubs, vines and roots 
and for separating the ruljljer from the bark and wood. In this A 
represents a steam boiler, while B is s. casing containing a vertical 
bucket conveyor which receives the shrub through the door C. The 
charge is raised to the top and conveyed through a chute B into a 
circular casing E. This contains a spiral conveyor E and several pairs 
of rollers G which crush the shrub as it passes thri:;Uiih the casing. 
The conveyor and rollers are driven Ijy the gear H. When the material 
reaches the opposite end of the casing it falls through the hopper I 
into a second casing J. which is similar to the first, in that it contains 
a spiral feeder and crushing rollers. During the passage of the 
crushed shrub, a part of the finely divided bark and wood falls through 
the holes K into a shaking sieve L, while the coarser particles pass 
through hopper d/. The bark and wood fall into the dust hopper N^ 
while the rubber, which coheres in larger pieces, passes through the 
hoi)per and between the crushing and washing rollers B, which 
further separate the rubber from foreign matter. An endless band 
conveys the material back to the top of the rollers or to a discharge bin. 




Fig. 270. — Guayule Blocking Press. 



EXTBACTION OF RUBBER AXD GUTTA 



265 



GUAYULE BlOCKI]S^G PkESS. 

The press illustrated in Fig. 270 is an ordinary toggle joint press 
equipped with a collapsible frame for forming wet rubber into blocks. 
The frame is shown closed and filled and ready to be pressed. This 
is practically the same type of press that is used all over the world 
for blocking plantation rubber — often a screw and sometimes a hy- 
draulic jDress. This particular toggle joint press makes a block 23% 
X 9% X 6. The forming box is lined with loose steel plates to keep 
the gTim from sticking. 

The Palmer La^^doephia Decoeticatoe. 
In Fig. 271, A is the frame in which are journaled fourteen 
corrugated rollers B. Each roller carries a worm gear C and engages 
a worm shaft D, belt driven from the main shaft G, and all rotate 




Fig. 271. — The Palmer Laxdolphia Decorticator. 



simultaneously in the same direction. Two shafts, G and F, journaled 
in the upper part of the frame, are driven in the same direction. 
Each shaft supports four rows of steel rods E, which are pivoted in 
the shaft hubs and have their outer ends grooved. When the shafts 
are rotated the centrifugal force keeps the rods extended. The vines 
are fed into the machine by the revolving bed rollers and the rapidly 
revolving rods act as hammers and separate the rubber and fiber. 

The GriGEET Ceusher axd Exteactoe. 
Fig. 272 shows a front elevation of this machine. The engine 
M drives the crusher B and the agglomerators E, F and /. These 
are coned-shaped and ribbed and revolve in steam jacketed ribbed 
sleeves. The vine or shrub is fed through a hopper A into the crusher. 
Here it is shredded and treated with water. It then passes through 



266 



RUBBER MACHINERY 



a channel C and a two-way funnel D, into the agglomerators E and F. 
Most of the wood particles are washed away by a stream of water 
while the rubber forms in masses. On leaving the agglomerators E and 
F the rubber passes into a trough I, which conducts it into a rotating 
screened drum (not shown), where more of the wood particles are 




Fig. 272. — The Guiguet Crusher and Extractor. 

washed away, while the rubber remains on the screen. It is then 
passed through the final aggiomerator J, where the rubber is formed 
into shape convenient for handling. 



The Yalouk Extractoe. 
In Fig. 273 is shown an end elevation of this machine, which is 
but a modified form of a tumbling barrel. The drum A is mounted 
in side frames B and driven by a belt pulley. The body of the drum 
is perforated and the inside has broad alternating convex and concave 
ribs G and D. Metal rollers E of small diameter and about the same 
length as the drum are loosely placed on the inside at the bottom. The 
shrub is fed to the machine through doors on the side or ends. Water 
is supplied through the hollow shaft bearings. AVhen the drum is 
slowly revolved the rollers rotate and tumble about thereby pulverizing 
the shrub. The fiber is carried away through the perforations by the 
water and the rubber remains in the drum. 



EXTRACTION OF RUBBER AND GUTTA 



2r3T 




Fig. 273. — The Valour Extractor. 

The Kempter Peocess of Extractixg Rubber. 
The apparatus shown in Fig. 274 is a German invention for 
extracting rubber from plants. A is a tank with a water inlet and 
outlet. Suspended in the tank is a cylindrical casing B with a per- 
forated bottom C and a hopper-shaped top D. The shaft E is journaled 
in bearings (not sho\^al) and support radial arms F. These are as 




Fig. 274. — The Kempter Process of Extracting Rubber. 



long as the casing and have corrugated rubbing surfaces that conform 
to similar roughened surfaces of the casing D. The tank is filled 
with water and the plants are fed into the hopper. The revolving 
roll carries the leaves or plants between the roughened surfaces, which 
reduces them, the fine woody particles are washed out through the 
screen while the rubber rises to the surface of the water. 



268 



RUBBER MACHINERY 



The Kigole Gutta Peecha Extkactoe. 
A French apparatus for extracting gutta percha from leaves, 
bark or twigs is shown in Fig. 275. The leaves or twigs are first 
pounded and then placed in an exhausting vessel A. Carbon bisulphide 
is placed in a water boiler B and passes through a tube C, as a vapor, 
into the condenser D. Here it is condensed and percolates through the 
leaves and twigs. The liquid then returns to the water boiler B 
through the tube E, the strainer G and the automatic valve F. After 
the solvent has dissolved and transferred a portion of the gutta to the 
water boiler, it again passes through the tube C and is condensed in the 




Fig. 275. — The Rigole Gutta Percha Extractor. 

vessel A to dissolve more 2;um. When all the ffum is dissolved and 
carried into the boiler, the valve H is closed. A jet of steam is then 
introduced from the steam boiler I through the vessel A and the boiler 
B. This carries away the excess carbon bisulphide into a tank J, 
while the extracted gutta percha remains in the boiler B. 



The Seruleas Gutta Peecha Exteactoe. 
Pef erring to Fig. 276, the pulverized gutta percha leaves and 
branches are placed on a filter F in the jacketed digester A which is 
then closed. The solvent toluene passes from a refrigerator C to a 
steam jacketed reservoir B. Here it is heated and then passed into the 
digester A, where it is mixed with the material by an agitator D. 
After sufiicient time has elapsed the solution is discharged into the 



EXTRACTION OF RUBBER AND GUTTA 



269 




Fig. 276. — The Serullas Gutta Percha Extractor. 



still E, where the solvent is driven off by distillation, 
percha is then sheeted and dried. 



The gutta 



The Obach Gutta Percha Extractoe. 

This process is based on the fact that gutta percha is soluble in 
light petroleum spirit at the boiling temperature^ but is re-precipitated 
on cooling below 60° F. 

Referring to Fig. 277, the crushed and dried leaves are placed in 
a wire basket and lowered into the steam jacketed digester A. It is 
then filled with naphtha from tank B or F, and heated to the boiling- 
point while the vapors are condensed in C. The solution in A is 
allowed to cool and is then drawn off into a tank D^ fresh naphtha being 
admitted and the operation repeated. After draining, the remaining 
solvent is distilled through C into tank E, and the exhausted leaves 
removed. The gutta solution is then pumped into tank B and from 



270 



BUBBER MACHIXEBI 



there it flows through a fresh charge of leaves or the giitta is cooled 
down in one of the digesters and precipitated. The mother liquor is 
then drawn off into tank D, the precipitate washed with clean naphtha 
from tank F and allowed to drain. Steam is now admitted to the 
digester to distill off the remaining naphtha, and the gutta which is 
found floating on the condensed water removed and washed. The 
digesters A and G are worked alternately. 



^. 




^ 



h/^%^ 




Fig. 277.— The Obach Gutta Percha Extractor. 



CHAPTER XVI. 

EXTRACTIOiS; OF RESII^S FROM RUBBER AND 
aUTTA PERCHA. 

NEARLY all wild crude rubber coutahis resin, some having more 
resin than rubber. The amount of resin found in rubber ranges 
from. 1.2 per cent, in fine Para to 75 per cent, in Pontianak. 
In spite of the variety of soft resins found in some grades of rubber, 
extraction has been successfully done on a large scale. 

India rubber which has undergone complete oxidation consists 
principally of a hard, brown, transparent substance, shellac-like, called 
Spiller's resin. This resin is an acid ; it combines readily with soda 
and potash, forming soaps which are soluble in cold and hot water. 
Spiller described this resin many years ago. The variability in the 
amount of resins which may be found in the various classes of rubber 
is illustrated by the results of analyses made by Lyman M. Bourne.^ 
His table covered 181 analyses of all classes of rubber, and the results 
of a few" of the more important are given here. 

Three samples of Ceylon Para fine averaged 2.5 per cent, resin 
and 97.5 per cent, rubber, with no shrinkage, this being the only variety 
without shrinkage. The average of 23 samples of Brazilian Para 
fine showed 96.6 per cent, rubber and 3.4 per cent, resin, with 17 
per cent, shrinkage. Six samples of prime Assam, from India, showed 
15.8 per cent, resin. Two samples of Borneo second and one of Bor- 
neo third showed 19.3 and 20.7 per cent, resin, respectively. Seven sam- 
ples of Upper Congo gave 13.8 per cent, resin. One sample of Brazilian 
strips showed 28 per cent, resin. Three samples of Mexican Guayule 
showed 25.4 per cent, resin and 25 per cent, shrinkage, and seven 
samples of Pontianak showed 75 per cent, resin and 60 per cent, 
shrinkage. 

In analyzing these samples they were dissolved in benzol and 
the resin was precipitated by addition of alcohol, the gum remaining 
in solution. Dr. Weber, in his work on the analysis of rubber, advises 
that samples l)e treated by the Soxhlet method of extraction, using 
acetone as a solvent of the resins while the rubber is not dissolved. 

The extraction process begins with washing and drying the raw 
material in the ordinarv wav. If the resin solvents will dissolve 



*See the India Rubber World, Dec. 1, 1906 page 75. 



272 RUBBER MACHINERY 

water it is clieaper to extract the water with a portion of solvent and 
then put on a fresh portion to extract the resin. There are two ways 
of dissolving out the resin. One way is first to put on a solvent for 
both rubber and resin, like naphtha. Then the gum is precipitated 
out by acetone, leaving the resin in solution. 

The other method is to use a resin solvent only, such as acetone, 
without dissolving the rubber. 

By using a rubber solvent the rubber is softened so that the 
resins can be easily extracted. This is done by placing the rubber 
and solvent in a tight cement-mixing apparatus. (See chapter on 
Cements and Solutions.) A simple condenser is used to condense the 
solvent vapor. When the rubber is sufficiently softened, the resin 
solvent — acetone — is let in and the stirring continued. The rubber 
finally masses, when the acetone containing the resin is drawn off. 

Using the other method, it is necessary to thoroughly work the 
rubber with the solvent. In fact it must be washed with solvent just as 
it is customary to wash dirty rubber with water, but there must be 
no exposure to the air. 

There are also processes for deresinating by the use of alkalies, 
but such processes have not been used on a commercial scale. 

Almost all of the "enclosed" washers, notably the Hood washer 
(see Chapter I, Fig. 10) may be and are used in deresination. The 
machines that follow are used only for the extraction of resins from 
rubber. 

The Chute Deresinating Appaeatus. 

This is shown in Fig. 278. 

The fiYQ extractors, A, B, C, D and E have steam heated jackets 
F and contain rotating macerators G. These extractors communicate 
by pipes with three kettles H, I and J, which are connected Avith two 
fractional distilling columns K and L, goose necks M and N, condenser 
and P, and finally with solvent tanks Q, R and S. A mixture of 
methyl acetate and acetone is used. There is also a condenser T con- 
nected directly with the tanks and a pump U for forcing the different 
materials through the pipes. With low grade, wet rubbers the operation 
is as follows : 

The rubber is placed in tank A and the macerator G is set in 
motion, while steam is admitted to the jacket to hold the solvent near 
a boiling temperature. Dehydrating solvent from tank B, which has 
already been used to partially dry a batch of rubber, is passed into A 
through the pipe Y. This solvent, after extracting the greater por- 
tion of water from the rubber, is discharged into one of the kettles. 



EXTRACTIOX OF BE SIX S 273 

The rubber in A is now treated with fresh soh'ent, and after being 
thoroughly agitated with the rubber the solvent is passed into another 
extractor and used again. The rubber, which has been treated twice 
with dehydrating solvent, is now treated to extract the resin. Solvent 
which has been used to treat other rubber is admitted to A. and mixed 
with the rubber. It is then drained off into one of the kettles II, I or 
J, and the rubber is treated with fresh solvent. After taking up all 
the resin it will hold, this solvent is discharged into another tank 
to be used again, and the rubber is washed and dried. 




Fig. 278. — The Chute DeresinxKttng Apparatus. 

The rubber in each extractor may be treated in the manner 
described for A, by manipulating the valves, and in practice four of 
the tanks are being worked with solvent and rubber while the fifth 
is treated with water and recharged. The columns K and L are pro- 
vided for the fractionation of low and high grade solvents, each being 
fed by one of the vapor lines V. The exhausted liquid is returned to 
the kettles through the lines TT. Any uncondensed vapor is condensed 
in and P and finally returns to the solvent tanks to be used a^ain. 



The Eves Peocess. 
In Fig. 279 ^ is a large, shallow tank containing a steam coil B 
and drain pipe C. Mounted above this tank is tank D, the upper end 



274 



RUBBER MACHINERY 



being closed by the head E. The vertical shaft F has agitator blades 
G at its lower end and is driven by a belt pnlley H. It is snpported 
in the center by spider I which moves vertically with the shaft when 
it is raised and lowered. The two tanks are separated by a corrugated 
screen J. The upper tank has a door K, through which a perforated 
kettle L is introduced. This kettle is mounted on rollers and rests 
on rails M. In the upper end of the tank Z> is a condensing coil N. 
The operation is as follows: The shaft F is raised vertically and the 




^^m 



Fig. 279. — The Eves Process. 



door is opened. The kettle containing the rubber is then run in the 
tank, the agitator shaft is lowered in place and the door closed. 

The tank A is partly filled with alcohol which is volatilized by the 
heating coils. The vapor passes up between the tank D and the kettle 
L and is condensed by the coils N. The liquid then drops into the 
kettle, being prevented from running down the sides by the flange 0. 
The agitators keep the rubber in motion so that the alcohol is thor- 
oughly mixed with it. The resin is dissolved by the alcohol and drops 



EXTRACTION OF RESINS 



275 



througli the perforated base of the kettle and the screen /into the 
tank A. When all of the resin has been removed, the agitator shaft 
is raised, the door opened and the kettle rnn out for the removal of 
the deresihated rubber. The solution in tank A is drained off through 
the pipe C and is later distilled to separate the resin from the alcohol. 

, The Laweexce Deeesixatoe. 

The Lawrence process of refining Guayule separates the resins and 
also water and naphtha from the rubber. Fig. 280 shows a macerator 
tank A, an evaporator B, a condenser C, a separator D and a series of 




The Lawrence Deresinator. 



storage tanks, alcohol in E, recovered naphtha in F, naphthalized alco- 
hol in G, and watered alcohol in H. Each of these receivers is pro- 
vided with vapor vents, gages and inlet and outlet pipes. In tank A is 
a vertical shaft / bearing four horizontal rollers J at its lower end. 
This agitator is slowly driven by a belt K and when not in operation 
it is lifted out of the tank by the chain block L. The process is as 
follows : 

The rubber is placed in the jacketed macerator A and spread 
evenly over the bottom. Through the pipe M from the tank H alcohol 
is drawn into the tank A. The condenser C is packed with ice and 
salt, and the valves in pipes N, and P are opened. Steam is admitted 
to the tank A, heating the alcohol to about 122 degrees F. The vapor 



276 



BUBBEB MACHIXEBl 



is conducted by tlie pipe X to the condenser and is recovered in the 
separator D. The alcohol in tank A becomes saturated with resin and 
naphtha. This solution is drawn off through the pipe Q into the 
jacketed evaporator B, and the steam is turned on. The contents are 
vaporized and conducted into the condenser through the pipe S, the 
resin remaining in the tank B. The pipe Q is now closed and a second 
charge of alcohol is drawn into the tank A, when practically all of 
the naphtha and resin in the gum are extracted. This second charge 
is drawn off and evaporated as before. The deresinated rubber is 
remove<l from the tank A by raising the agitator and cover by the 
chain block L. Practically all the alcohol and naphtha is recovered 
in the separator D. Where rubber containing bisulphide of carbon is 
to be 23urilied. a separate tank B is provided, on account of the dis- 
agreeable odor of this chemical. 

The La^vee^'Ce Deeesixatoe. — fAH'aJl Brocess.) 
In Tig. 2 SI. A represents a steam-jacketed kettle containing an 
iilkaline solution, usually 10 per cent, solution of soditim hydrate. 




Fig. 281.— The Lawrence Deresixator (Alkali Process.) 

After l-ioiling the rul>l«er in this solution for half an hour with constant 
stirrino;-. the resin is completely dissolved and the rubber is broken 
up into small particles so that the contents of the kettle may be drawn 
off through the pipe B and emptied upon a moving strainer C. The 
alkaline solution, with the resin, is drained into the trough D while the 
deresinated rubber is partially washed by the sprinkler E and then 
conveved to the washing tank F, where it is thoroughly cleansed and 
rolled into sheets. 

The Teamaxt Coxtixuges Peocess. 
This is a deresinating apparatus which operates continuously, 
without loss of time, and renders subsequent manipulation unnecessary. 



EXTRACTIOX OF RESINS 



277 



The solvent may consist of ethyl or methyl alcohol or acetone mixed with 
petroleum, carbon tetrachloride, benzine, ether or carbon bisulphide. 
Fig. 282 shows a steam jacketed still A for evaporating the solvent; a 
tank B for purifying the vapor and for heating the solvent ; a con- 
denser C and a tank D in which the resin is dissolved. A number 
of cylindrical discs of wire netting are arranged in this tank so that 
the solvent can circulate freely between them. 

The vapors from still A pass through the pipe E into the tank B 
and through three rectifying plates F which dehydrate them. The 
vapors then pass over the coils G^ through the pipe H and the con- 




FiG. 282. — T?iE Flamant Continuous Process. 



denser C, where the vapors are condensed. The solvent then passes 
through the pipe I and the heating coils G, and then into the extract- 
ing tank D. The rubber to be deresinated is placed on the discs in 
this tank and subjected to the hot solvent. This removes the resin 
and carries it over into the still A, where it is deposited. The pipe /, 
through which the resin and solvent pass to the still and which is in 
the shape of a siphon, keeps the extractor D full of solvent. Vapors 
condensed in the tank B are returned directly to the still through the 
pipe L. 



27S 



BUBBER MArHIXEBI 



first introduced bv Obach, is shown in Fig. 2 S3, 
has a perforated bottom covered with wire gauze. 



The Obach Gutta Pekcha Peocess. 
The chemical deresinating and hardening process for gutta percha. 

The inner tank .1 
This tank is filled 
with gutta percha. which has been pre^-iously cut in pieces and 
thoroughly dried, and lowered into one of the tanks B. This is 
repeated tmtil the three tanks B have been charged, when naphtha 
from tank C is admitted. The solution, containing a large amotmt 
of resin, is run from the last tank B into tank D and from there into 
still E, and the solvent vapor is condensed in F. 




Fig. 2$3. — The Obach Gutta Percha Process. 

The spirit from tank A is then run off into another tank and 
the gutta percha washed with clean spirit. The inner tank containing 
the gutta percha is lifted out and the latter discharged into the mas- 
ticator (t. previously filled with cold water. The masticator is then 
closed, steam is turned on and the roller set in motion to knead the 
gutta percha while the solvent is being distilled off" and the vapors 
condensed. The resinous solution is distilled in E and the deresinated 
gutta percha is removed, washed, dried and sheete<:l. 

The Haddax Resix Exteactoe. 
In the process shown in Fig. 2S4. the gTitta percha is treated with 
carbon bisulphide and filtered to remove the mechanical impurities. 



EXTBACTIOX OF RE SIX S 



279 



The solution then passes into a series of depositing vessels, where the 
oxidized gutta percha separates from the non-oxidized material owing 
to a difference in densities. The oxidized product is deoxidized by 
means of carbonic oxide and the two gutta percha products are then 
treated with a solvent such as benzine or turpentine to extract the 
resin. These operations are carried out in the apparatus shown, in 



. JJ r*J nt* ~^ :^*« :^*^ 


^+4 


ibfao^ 


it'll . yi[,ir 


c 


c c 


U4- 



Fig. 284. — The Haduan Resin Extractor. 

which A is the receiver or mixer, B the filter, C the depositing vessels 
and D the evaporator in which the carbon bisulphide is evaporated. 
The vapor is condensed in the vessel E, containing cooling coils, and 
the condensed solvent is collected in the reservoir F. In the second 
series of operations, the bisulphide is replaced by benzine or other 
solvent to extract the resin. 



The De La Feesxaye Deresixatoe. 

In Fig. 285 is shown a French apparatus for extracting resin 
from gutta percha. A is a steam heated tank, connected with a naph- 
tha tank B by the pipe C. The lower end of tank A communicates 
with the collector D by the pipe E. The collector D is connected with 
still F which communicates by a pipe G with the reservoir B. At its 
upper end the still is connected to the tank A by the pipe II. 

The crushed gutta percha is placed in the tank A and covered 
with naphtha and the temperature gradually raised about 35 degrees C. 
As long as the solvent remains colorless only resin is being dissolved, 
but any discoloration of the solvent indicates that the gutta percha is 
also beginning to dissolve. Before this occurs the solvent containing 
the resin is run off into the tank D, while the gutta percha remains 
in the tank A. The solvent is recovered by distillation and the resin 
collects in the tank D. The solvent remaining with the gutta percha 



280 



RUBBER MACHIXERY 




Fig. 285. — The De La Fresxaye Deresixator. 

is recovered tliroiigli tlie pipe H in the still F, from which it returns 
with that already recovered from the collector through the pipe G into 
the reservoir B to be used again. 



A Feexch Peocess. 

The rubber is first treated with carbon bisulphide, benzine, or 
carbon tetrachloride and afterwards with a substance for dissolving 
the resins such as methyl alcohol or acetone. In Fig. 286, C is a steam 
jacketed masticator. B B are two revolving blade shafts. D c-bntains 
the rubber solvent. E contains the resin solvent. F is a vacuum pump. 
G is a steam jacketed evaporator. H is 8. condenser. 

The rubber is first agitated in the masticator with a quantity of 
the rubber solvent, then with the resin solvent. The solvent containing 
the resins is then collected in G by decantation — tipping the masticator 
C on its support. This is repeated several times to secure complete 
extraction of the resins. The vacuum pump is used for extracting 



EXTRACTION OF RESINS 



281 



the remaining solvents in the masticator. The liquid solvents are 
separated in the evaporator and the vapors recovered in the condenser 




Fig. 286. — A French Process. 

and returned to their respective reservoirs. The purified rubber is 
collected in the masticator, while the resins remain in the evaporator. 

A Gekmax Deeesixatoe. 
The apparatus shown in Fig. 287 is for extracting resins from 
low grade rubber such as Pontianak. It is a double apparatus, having 




Fig. 287. — A German Deresinator. 



282 BUBBEE ^LiCHIXEEY 

two steam jacketed extractors A, two steam jacketed stills C, two 
condensers E and a solvent tank B. 

Tlie rubber is first dried and formed into long rolls, which are 
placed on perforated trays in the extractors A. After they are closed 
the rubber is covered with solvent from tank B and heated. The 
solvent, which has become saturated with resin, is then run into the 
heated stills C, where it is agitated by stirring blades operated by 
belt pulleys D. The solvent vapor passes into the condensers E and 
returns in liquid form to the reservoir B, by way of the siphons F. The 
rubber in the extractors A is again subjected to the action of the 
solvent and the latter is run into the stills to be again evaporated, 
condensed and returned to the reservoir. The process is repeated until 
all of the resin has been removed from the rubber. The latter is then 
washed and dried. Either one or both sets of apparatus shown in the 
drawing may be employed. 



CHAPTER XVII. 

KECLAIMI^^G. 

f^T^HE reclaiming of rubber from vulcanized waste has made remark- 
I able progress within the past two decades. The improvement in 

processes has been marked, the extent of the business has developed 
wonderfully and the use of the product has increased more rapidly 
than the consumption of crude rubber itself. 

The reclaiming of waste rubber can be divided into three groups — 
the mechanical, the acid and the alkali processes. In the first, or 
mechanical, the waste is first ground to a fine powder, and if fabric is 
present it is blown or sieved out by the use of compressed air or screens. 
If metal is present it is removed by magnetic separators. The rubber 
is then devulcanized, after which it can be sheeted or batched. E'ext 
is what is known as the acid process. In this the rubber containing 
fabric is first shredded on a cracker and is put in a tank containing 
sulphuric acid and water. The stock is then boiled long enough to 
char the fabric, after which the rubber is washed in clean water to 
free it from the surplus acid. It is then dried and run through a mag- 
netic separator to remove particles of iron. Some manufacturers run 
it through what is known as a rifiler — a long trough containing obstruc- 
tions through which a stream of water is running. The riffles retain 
the sand and metallic particles which the magnet does not remove. 
It is devulcanized, then sheeted or run through a refiner, or through 
a strainer similar to a tubing machine. In the third, or alkali process, 
the rubber and attached fabric are subjected to treatment with caustic 
soda and water. After devulcanization, the rubber is washed to free it 
from the alkali, dried, sheeted and refined in the same way as in the 
acid process. 

The Sullivan Baliistg Press. 
Baling presses are used by scrap dealers to put the waste in port- 
able form. They are also used by rubber manufacturers who send 
vulcanized trimmings to the reclaimers. They are of many sorts — 
lever, screw, toggle and hydraulic. Pia;\ 288 shows one of the simplest 
forms. It is simply a strong wooden box, filled with scrap. A heavy 
plate at the top is forced down upon the mass and partly into the 



284 



RUBBER MACHINERY 




Fig. 288. — The Sullivan Baling Press. 

box, compressing the contents into a bale. It is operated by two levers, 
one on each side, that work in ratchets. 




Fig. 289. — The Logemann Baler. 



RECLAIMING 



285 



The Logemann Balee. 

Fio-. 289 shows a toggle lever baling press built of steel. It is 
operated by an adjustable crank and gears, which revolve the main 
driving screw at different speeds. Threaded on the screw are two 
toggle levers to which the compression plate is attached. The screw 
and lever construction gives a very high compression and produces a 
compact bale. 

x\lligatoe Sheaes. 

^Yhen the scrap is in too large pieces to be easily handled on 
crackers or shredders, it is cut into pieces of convenient size by such 
appliances as alligator shears. Such a machine is illustrated in Fig. 
290. The upper blade is pivoted and of heavy steel. The lower is 




Fig. 290. — Alligator Shears. 



both table and shear and is stationary. The movable blade is driven 
bv tiaht and loose pullevs, with back p-eariup- and a balance wheel. The 
Farrel shear, for example, is made in three sizes. One has blades 
10 inches long making 40 cutting strokes a minute; another 12-inch 
blades making 25 strokes a minute, and the third has 15-inch blades 
and makes 20 cutting strokes a minute. The crank motion that opens 
and closes the shear is extremely simple and can be readily understood 
by a glance at the illustration. 

The Gubbins Cutter. 
Before scrap is shredded it is often necessary to remove parts 
that cannot be reclaimed, as, for example, the wire from wire wound 



286 



RUBBER MAC Ely FRY 



hose. Fig. 291 shows the Gubbins cutter used for this purpose. The 
hose is first flattened by the rollers A and B, and then slit longitudinally 
by the circular cutter C. The half sections are then grooved deeplv 
by the cutters D and cut into short lengths by the cropping cutters on 




Fig. 291. — The Gubbixs Cutter. 



the ends of the rollers A and B. The rubber is then easily separated 
from the wire. 

The Johxstox Bead Teimmek. 

Tire beads are not often reclaimed but are cut off and destroyed. 
The machine shown in Fig. 292 cuts oft' both beads of quick 




Fig. 292. — The Johxstox Bead Trimmer. 



RECLAIMING 



287 



detachable or clincher tires in one operation. It has a crowned 
roll A driven from the motor B by gears C and D. Two pressure 
feed rolls, covered by shields F, are held in contact w^ith the roll 
A by springs G. Back of the feed rolls are circular knives covered by 
shields and held down by springs /. The tire is cut and one end 
fed into the machine under the rolls, and the circular knives sever 
the beads from the casing. The cutters are adjusted to cut off beads 
of all sizes of tires up to 6 inches. With two operators, the capacity 
is 25,000 pounds in ten hours. 

Shredders^ Geixders and Pulverizers. 
Before scrap rubber can be treated for devulcanization, desulphur- 
ization or fabric removal, it is cut, shredded and powdered. An ordinary 
way is to use an alligator shear, a cracker and a heavy mixing 
mill. There are, however, a variety of cutters and pulverizers used, 
which are often more efficient. 



The '^Giaxt'^ Scrap Cutter. 
Fig. 293 illustrates a machine for cutting waste into shreds. The 
main shaft G is driven by the belt pulley H and has mounted upon it 
a sprocket wheel which drives the roller i? by a chain I passing over the 

-J 




Fig. 293. — The "Giant" Scrap Cutter. 



large sprocket wheel -/. The waste is fed into the box A and passes 
under a spiked roller B. It is then cut by the three fly-knives G 
mounted on the revolving drum D, the cutting being done against the 



288 



RUBBER MACHIXERI 



statiouarv bed knife E. As the rubber is cut it falls into a receiver 
under the table or upon a moving apron passing over the roller F. This 
cutter will shred the heaviest tires. It has a capacity of 2.500 pounds 
per hour and requires from KJ to 12 horse power to operate at 500 
E. P. ]\I. The machine weighs 3.500 pounds and requires a lloor 
space of 64 x (34. 

Rotary Cutter. 
Tig. 294 shows a rotary cutter, which has five lly knives revolving 
in a circular case, to the walls of which are fastened six statiouarv 




Fig. 294. — Rotary Cutter. 



knives. The knives are straight, being set at an angle to insure a 
shearing cut. and are easily sharpened. The scrap is fed in a hopper 
at the top and as it is cut passes over a perforated plate which forms 
the bottom of the case. When fine enough it falls through a perforated 
plate at the bottom, otherwise it is carried around and cut again until 
it will pass through the perforations. The plate is removable so that 
another with different sized holes may be substititted. These detei- 
mine the size of the product. The Xo. 1 machine weighs about 1,300 



RECLAIMING 



289 



pounds, and requires 5 to 15 horse power at 600 to 900 R. P. M. It 
may be used for anv kind of scrap, including hard rubber. 



The Kimble PueveFvIzee. 
The machine in Fig. 295 was designed to pulverize various spars, 
mica and aluminous compounds. It has been found, however, to give 
excellent service in reducing vulcanized scrap to a fine powder. 
Described briefly, it consists of two integral casings like intersecting 
circles with trough-like bottoms. The two shafts B and C journaled 
in the side-frames A, support beaters D. These are arranged spirally 
on each shaft. The pitch of the spiral on one shaft is different from 
that on the other; the beaters on one shaft passing, when in motion, 
through the spaces on the other. The machine is fitted with a feed 
and with an exhaust for removing the pulverized product. 




IT \r 

Fig. 295. — The Kimble Pulverizer, 

These machines are often run in a series of three. The first 
takes coarse scrap, cracks it roughly and passes it on to the second; 
this makes a finer division, and the third further reduces the scrap 
and passes it to the pulverizer, which reduces it to a fine powder. It 
is then removed by an exhaust fan, which separates the fiber from 
the rubber. 

The Gare Powdeking Machine. 

Fig. 296 shows a machine which is a rasping device for powder- 
ing vulcanized rubber scrap. The drawing on the left is a sectional 
view of the pulverizing mechanism, while that on the right is a front 



290 



BUB BEE MACHIXEEY 



elevation of the whole machine. It is nionnte;! on a base consistin*^- 
of a hollow casing which supports the main shaft driven by tii>ht and 
loose pulleys F. The drum D is keyed to this shaft and has a rasp- 
like surface. The feed device consists of a spiked roller .i and six 
spring rollers B, between which the rubber (' is fed against the rasp- 
like surface of the drum. The roller A is rotated intermittent! v bv 





Fig. 296. — The Gare Powdering ^^Iachixe. 



a ratchet wheel E . driven by a ratchet lever and cam on the main shaft. 
The rubber is fed forward a short distance at each revolution of the 
driving shaft, and the ground ruldier drops into the casing below the 
drum. 

The Mitchell Grixdixg Process. 
In the process illustrated in Fig. 297 three crackers are employed. 
The rubber scrap is cracked on the lirst mill ( which is not shown) 
and conveyed by a moving apron to the second mill A, which has a 
roll B with line corrugations and a roll (' with coarse corrugations. 
Here, after the rubber has been further reduced, it falls on an inclined 
guide D which conducts it to the lower end of a screw conveyor E. 
This raises the rubber to an inclined screen F, through which the fine 
material falls, while the larger pieces pass between the rolls G and // 
of the third mill /. Both rolls of this mill are finely corrugated and 
reduce the scrap still further. The reduced rubber, both from the 



RECLAIMING 



291 




Fig. 297. — The ]\Iitchell Grinding Process. 

screen F and the mill rolls, falls npon an inclined gnide J , which 
delivers it to a receiving bin. A rapid oscillatory motion is given to the 
screen F to assist in separating the fine powder from the coarse pieces. 

The Gakdxee Disixtegeator. 
Fig. 298 shows a side view, partly in section, of a machine for 
disintegrating scrap rnbber. It is monnted on a base which supports 
the main shaft. The abrading wheel is keyed to this shaft and is 
driven by a tight and loose pulley. The scrap A is placed in a sliding 
box B, the bottom and sides of which are perforated for ventilation. 




Fig. 298. — The Gardner Disintegrator. 



A fan circulates a current of air through the rubber to prevent heat- 
ing. The box is fed forward by a weight C, and the scrap is abraded 
by the rapidly revolving wheel D faced with emery or carborundum. 
The ground rubber falls throuoh a screen E into a removable bin F. 
When the box B has reached the end of its forward travel it is pulled 
back for refillino* bv hand wheel G which raises the weight C. 



292 



RUBBER MACHINERY 



The Williams Sheeddks^g Maciiixe. 

In Fig. 299 is shown a sectional elevation of a machine for 

shredding boots, shoes, etc. The scrap is fed into the hopper A and 

conveyed by the revolving rollers B to the feed rollers C and I). As 

the rubber passes through these rollers and over a stationary triangular 




Fig. 299. — The Williams Shredding Machine. 

cutting bar it is shredded by the ends of rapidly revolving hammer 
bars E. The material which w^ill pass through the screen G is dis- 
charged from the machine, otherwise it will be reduced by the hammers 
until it passes through the screen. The particles of fabric are blown 




Fig. 300. — Separating Rubber and Fabric. 



RECLAIMING 



293 



from the cage througii a pipe II by an exhaust fan I. The feed is 
automatically stopped if pieces of metal or stone pass between the 
rollers. 

Sepaeatia^g Kubber and Fabric. 
Debauge's process consists in first treating rubberized fabric with 
a solvent which sw^ells the rubber and loosens it from the fabric. Refer- 
ring to Fig. 300, the treated fabric is fed into the machine from 
either end, between the rollers A and the circular brushes B. The 
brushes revolve at a higher speed than the rollers A, and remove the 
rubber from the fabric. The rubber falls in the bin C and the solvent 
vapors are drawn off through the pipe D for subsequent recovery. 

Fiber Separators. — {Dry.) 
Getting the fiber and foreign material out of powdered rubber 
is done in two ways — by dry machines and by those that use water. 
Both types are described below. 

The Penther Separator. 
Fig. 301 shows a longitudinal vertical section of a dry separator. 
The rubber waste is fed into a hopper at the top of the casing A and 




Fig. 301. — The Penther Separator. 



is disintegrated in the cage B by the rotating arms C. The material 
falls through a grating into a chute D and on an oscillating sieve E, 



294 



BUBBEB MACEIXEBY 



the meslies of which increase in size toward the lower end. The light, 
jibrous material is blown upwards by a current of air forced through 
the pipes F and passes through an opening G out of the casing. The 
rubber falls through the sieve on an endless belt H. having cross l)ars 
I which travel in contact with the plate •/ and scrape the rubber off 
into the space K. As the material falls through this space, a strong 
ctirrent of air induced bv the suction fan B throtigh the pipe J/, 
enters through the adjustable llaps X. and deposits the light material 
in the chamber occtipied bv the endless band 0. The lighter filters 
are drawn through the pipe J/ and discharged, while the rubber, coarse 
fibers and particles of metal are carried along by the band 0, dis- 
charged into a screw conveyor P, and carried by an elevator liack to 
the sieve E, where it is again subjected to the sifting and sorting 
process. The flaps T are adjusted by outside levers to regulate the 
current of air passing through the space £^, according to the material 
to be treated. All the heavier material falls through the space K 
on a plate Q and is thrown by a rotating brtish B on an oscillating 
sieve »?. Here the material is subjected to a reverse air current pro- 
duced by the fan T. The fiber is blown into a conveyor B while the 
ruliber falls into a convevor T'. 




--n in 



Fig. 302. — A German Separator. 



RECLAIMING 



295 



A German Sepakator. 
In the Grummel machine, Fig. 302, the material is first disinte- 
grated and then placed on a reciprocating frame A mounted in a 
stationary frame B. Each of these frames has a screen made np of 
parallel wires. The frame A is oscillated by an eccentric mounted on 
the main shaft, and the fiber remains on the screen while the pulverized 
rubber falls through wires and is conveyed by C through chute D into 
a rotating drum E. This drum is conical and perforated with holes. 
It has an outer covering of metal and an inner one of leather, both 
perforated with holes coinciding with those of the drum. When it is 
rotated the heavy metallic particles are thrown against the vv^alls of 
the rotating drum and pass out through the perforations; or slits, 
while the finer rubber particles are conveyed by the screw F to the 
outlet G. The larger pieces of rubber not separated from the fiber 
pass out through the slits H and are caught in a receptacle / to under- 
go further treatment. 

Magxetic Sepaeatoes. 
One of the difficult problems in rubber reclaiming is to eliminate 
all iron. Overshoes contain it in the form of nails, buckles, stiffeners ; 
tires, in the form of tacks, nails, and bits of wire that have been 




Fig. 303. — The Mitchell Separator. 



296 RUBBER MACHINERY 

picked up on the roacl, and so on. For chemical as well as mechanical 
reasons, every particle of this iron must be eliminated, in order to 
make the reclaimed material of any value. 

The Mitchell Separatoe. 
This machine is illustrated in Fig. 303. The drawing on the 
left is a front elevation, and on the right is a side view. The rubber 
is first pulverized and delivered by a conveyor A to a hopper B, fall- 
ing by gravity across a plate C behind which are a number of perma- 
nent magnets D. Loose pieces of iron or steel are held by the mag- 
netized plate until removed by the scraping mechanism E. The same 
process is repeated successively in the hoppers F and G. Pieces of 
metal not removed by the first are held by the second magTietic plate 
H or the third plate /. These are also equipped with scrapers /. 
The rubber finally falls into a hopper K where the remaining iron 
or steel particles are held by the electro-magnet plate L. During the 
process a gentle exhaust is maintained by the fan M, which removes 
the dust from the rubber as it falls from one hopper to the next. 

The Eureka Separator. 
In this machine, Fig. 304, the pulverized rubber is run into a 
hopper. There a spiked feed roller keeps the rubber stirred up. Under 



Fig. 304. — The Eureka Separator. 

this roller is a corrugated feed roller which regailates the supply of 
material fed over the magnetized bed. The latter consists of a bank 



RECLAIMIXG 



29' 



of magnets laid side bv side in a vertical position about II4 inches 
apart. Over the poles of the magnets is placed a ^'keeper," consisting 
of a thin plate of tungsten steel. The bed of the machine is inclined 
so that the rubber passes over it bv gravity and the magnets hold the 
particles of iron or steel until removed by an automatic scraping device 
and deposited in a box at the end of the machine. 

The Dixgs Sepaeatoe. 
Fia'. 305 shows this machine, which consists of a lar2:e inclined 
magnetic table with a rubber belt traveling over it very slowly in an 
upward direction. The ground rubber is fed upon this belt from a 




Fig. 305. — The Dings Separator. 

feeding hopper. As the material rolls by gravity down the incline 
all particles of iron are held against the belt and carried upward 
over the top pulley and discharged into a box. The rubber falls from 
the belt and collects at the bottom of the incline. 



The Geist Sepaeatoe. 
This is of English origin. The illustration, Fig. 306, shows 
the drum only, over Avhich a feed hopper is placed. The point of 
interest in the Geist separator lies in the special construction of the 



298 BUBBER MACHIXEBY 

drum. On starting the machine an oscillating tray distributes the 
rubber upon a slide, which conveys it to the drum at a tangent. The 
drum is fitted with toothed projections which carry the material around. 
Inside the drum is a stationary magnet which can be adjusted at 
any arc of the circumference. The iron particles attracted by the 




Fig. 306. — The Geist Separator. 

magnet are held by the revoh'ing drum until they are no longer under 
the" influence of the magnet, when they fall off. The non-magnetic 
parts fall off in another direction. 

The Mitchell Defibeeizixg Taxks. 
The reclaiming apparatus illustrated in Fig. 307 was patented 
in 1881 and consists of a lead lined box A with perforated steam pipes 




Fig. 307. — The ]\Iitchell Defiberizixg Taxk. 



RECLAUnXG 



290 



B and removable covers C. By this process 60 deg. Be. sulphuric 
acid was added to the rubber and boiled v.^ith steam at 50 pounds 
pressure for about 5 hours. This dissolved the fiber but had no effect 
on the rubber. 

This in reality was the beginning of the acid process. Today, 
in dissolving fiber by acids, many kinds of tubs or vessels lined with 
lead are used, the steam being led in through a perforated lead pipe. 
AVooden stirrers are used, as they can be easily replaced when worn. 

The Mitchell Defibeeizixg Appaeatus. 

In Fig. 308 is illustrated the type of tank used in the largest 

plants. The tank A is lead lined and has a number of removable 

covers B. a flue C for the escape of vapors, and perforated steam pipes 

D. The rubber is conveyed to a hopper E and discharged into the 




Fig. 303. — The I\liTCHr.LL DefiBerizixg Aiparatus. 



tank through a chute F. AVhen the process is complete the gate G 
is opened and the contents of the tank discharged through the chute 
H. The tank is then flushed out with water from the pipe I. 

Washixg Tubs A:sr) Washers. 
Rul^ber scrap, after being deflberized, is run into a great vat 
known as the washing tul). where the aci:l or alkali is washed away. 
Mitchell's washing tub, illustrated in Fig. 309. is the common form 
of machine. It consists of a large circular vat A, in the center of 
which is a vertical shaft B, to which is attached a cross beam C , 
slightly above the top of the tub. ^Mounted on the cross beam are 
four vertical shafts, on the lower ends of which are plows or stirrers 
that can be set at any angle by a hand operated worm shaft. Directly 
behind the plows is a heavy conical roller E with wooden slats on its 
surface. The stock to be washed is discharged into the tub through a 



300 



RUBBER MACHINERY 



chute, and the shaft B is set in motion. The plows are set at the 
desired angle, by a handle F, to stir up the rubber and expose every 
particle to the action of the heavy roller E. The rubber is kept 
covered with water through the pipe G, and from time to time 
the gates H are opened to draw off the dirty water. After washing. 




Fig. 309. — The Mitchell Washing Tub. 

the plows are set obliquely to force the rubber toward the outside 
of the tub, and the discharge gate I is opened, allowing the stock to 
escape into a conveyor J , which carries it up into a trough K having 
a conveyor screw L in the bottom. This screw discharges the rubber 
into the hopper of the rotary washer 21, which is illustrated below. 



The Mitchell Rotary Washes. 
Referring to Fig. 310, this washer consists of a cylinder N, 
perforated with large holes at the upper end and small ones at the 
discharge end. It is inclined at an angle, being higher at the feed 
end. Inside the cylinder are longitudinal ribs 0, Avhich pick up 
the rubber and turn it over during each revolution. Surrounding 
the cylinder is a tank P, supplied with cold water through a pipe Q, 
and hot water, when necessary, through a pipe R. While the rubber 
is passing from the upper to the lower end of the cylinder impurities 
are washed out through the perforations, and the rubber is discharged 
into an elevator S. The drainage is through a pipe T, where fine 
pieces of rubber which pass out are caught by the sieve shown at U. 



RECLAIMING 



301 







Fig. 310. — The Mitchell Rotary Washer. 

The Solliday Washee. 
Fig. 311 illustrates SoUiday's washer. The upper drawing shows 
a side view of the complete apparatus, while the two lower drawings 
show details of parts of the machine. A is a long trough having an 
inclined chute B at its receiving end and a conveyor C at the dis- 
charge end. AVithin the trough are a number of paddle wheels B 




Fig. 311. — The Solliday Washer. 



driven by an endless sprocket chain E, which also operates the con- 
veyor. The trough is filled with water to the line F. In the bottom, 
between each pair of paddle wheels, is a tube G having a long opening 
H closed by a sliding gate /. The operation is as follows : 

The stock is fed into the trough and moved along by the paddle 
wheels, which keep it constantly stirred. Foreign material, such as 
sand, settles over the tubes G and is removed at the side of the trough 
by opening the sliding gates I. When the waste reaches the dis- 



302 



RUBBER MACHIXERF 



charged end of the trough, the foreign matter has been renio\'ed and 
the cleansed rnbl^er is picked up and carried out of the trough by the 
conveyor. 

The Claek Cleaxixc- Appaeatus. 
A phm view and a sectional side elevation of this machine are 
shown in Fig. 312. The narrow trough A, having at regular intervals 
gates or dams B, is set at a slight angle and is supplied with water 
through a pipe C. The ground rubber waste is fed into the machine 
at the upper end and passes through the several compartments and 
over the successive gates to the lower end of the trough, where it is 
delivered by a conveyor D over a screen E to a devulcanizer car, 
while the water passes through a screen to the sewer or a tank as 
desired. While the material is passing over the gates and to the 
screen, the refuse, such as sand, gravel or particles of metal, will settle 



a= 




Fig. 312. — The Clark Cleaxixg Apparatus. 

to the bottom of the compartments formed by the gates. These gates 
can be adjusted separately at any angle or moved all together l)v a hand 
wheel on a rod F. When a batch of stock has been run through the 
machine and it is desired to remove the refuse in the bottom of com- 
partments, the gates can all be raised simultaneously by a lever d. 
The conveyor D and screen E are then raised, and l)y turning on the 
water the refuse is easilv flushed out. 



The Askam Washer-Sepaeatop.. 
In Fig. 313 the pulverized rubber is fed by a screw conveyor A 
into a trough B. which is supplied with water from a pump f through 
the pipe D. The rubber is partly freed of impurities and passes into 
the trough E and then into the trough F. In these troughs is a series 
of dams G, which retard the flow of water and rubber while the heavy 
matter settles. The rubber finally passes into a settling tank H pro- 
vided with diaphragms I extending only part way to the bottom. Here 



RECLAIMING 



:i08 



the liglit foreign matter, such as chips, cork, etc., is separated and 
removed. The cleansed rnbber then passes throngh the pipe / and is 
deposited on the sieve L. An endless chain K having a series of brushes 
on its surface forces the fine particles of rubber through the sieve and 
removes the coarse. Below the sieve L is another chain brush M and 




Fig. 313. — The Askam Washer-Separator. 

a finer sieve N which also operate in the manner previously described. 
The water used for washing is caught in a tank and, after settlings 
is forced bv the pump C into the first washing trough B. 




Fig. 314. — The Koneman Washer-Separator. 



304 



RUBBER MACHIXERY 



The Ko^s^emax Washer-Separatoe. 
In Fig. 314 is shown an end view and a sectional side view of 
this machine. It has a U-shaped tank A swinging on a shaft B. 
Attached to the tank are circuhir racks C driven by pinions D for 
tipping it to remove the charge. Attached to B are a number of 
arms E, on the outer ends of which are rubber covered blades F which 
bear against the screen G forming the bottom of the tank. The rubber 
to be cleaned is placed in the tank and water turned on from the over- 
head pipe H. The shaft is set in motion and the blades keep the 
contents stirred up and allow foreigTi matter to wash through the 
screen. The water and refuse fall on the inclined platform I and 
are carried away through the trough /. After washing, the tank is 
tipped by the handle E to remove the rubber. 

The Simox Sepaeatoe. 
Simon's machine. Fig. 315. separates the buoyant or flotable 
materials from the rubber and convevs them from the machine while 



the heavier waste, 
tank. 



such as sand and dirt, sinks to the bottom of the 




Fig. 315. — The Simox Separator. 



In the accompanying drawing, which shows the machine in longi- 
tudinal section. A is a long tank containing water to the level A" A'. 
This tank has an inlet pipe C and drain pipes B and D. A partition 
E is located near one end of the tank, dividing it into compartments F 
and G. Mounted in the tank is an inclined trough H made of wire 
cloth. The trough is mounted on a shaft L and has a driving pulle\' 
M at its upper end. On the shaft are two series of helical conveyor 
blades N and 0, separated down to the shaft by the perforated apron P. 

During the washing operation a constant water level is maintained 
in both compartments. The rubber is fed into G and as the shaft 
is rotated the blades loosen the light foreign materials, which rise to 
the surface of the water and are prevented from passing into part F 



RECLAIMING 305 

by the screen P, while the heavier refuse drops through the perfora- 
tions of the trough. The rubber is forced under the apron P and 
conveyed along the trough, the heavy particles sinking to the bottom 
of the tank and the lighter ones floating on the surface of the water, 
where they are skimmed off. As the rubber is forced along by the 
blades it rises from the water and passes from the trough into a suit- 
able receptacle. 



CHAPTER XVIII. 

EECLAIMIXG {Continued). 

COXVEYOES. 

A VARIETY of l3elt. lincket and screw conveyors are used in car- 
rying the stock that is heing rechiimed. from one process to 
another. They are usually designed to suit the needs of the 
particular plant in which they are installed. 

The Mitchell Coxveyof.. 
Fig. 316 shows a belt conveyor A installed directly under the 
magnetic separator B, which was illustrated in Fig. 308. Chapter 




Fig. 316. — The AIitchell Coxveyor. 

XVII. The waste is lirst reduced on a cracker and fed into the mag- 
netic separator, which discharges directly on the conveyor belt. This 
belt runs on pulleys C and D and is supported by rollers E. Beneath 
the con\-eyor. near the discharge end, are bins F, G and H. The last 
of these is under the end of the belt and receives the material not 
removed before it reaches this point by the Idower 7. attached to pipes 
-/ and K, with nozzles directly over the belt. To remove the rubber 
from the belt to the first bin, the pipe K is closed by a valve and the 



RECLAIMING 



307 



fan blows the rubber from the belt against a screen L so that it falls 
into the bin F. The rnbber is removed to the second bin G by operating 
the air nozzle M in the manner previously described. A third pipe M 
is provided for blowing the dust from the conveyor after the discharge 
of the material. 



Fig. 317 



The Clark Conveyor. 
shows a plan of a system for conveying rubber waste 
from one apparatus through the different steps of reclaiming. The 
scrap is fed through a chute A to the cracker B and from it passes into 
a rinsing tank C. A conveyor D collects the rubber from the tank and 
discharges it into a second cracker E, from which it passes into a 
second rinsing tank F, The stock is then transferred by a conveyor G 




Fig. 317. — The Clark Conveyor. 

to a horizontal conveyor H, which delivers it to storage bins I and /. 
The rubber is treated in the tanks K and L to remove .the fiber, after 
which acid, water and rubber are discharged into the trough M. The 
liquid is drained off and the rubber, washed free of acid, is conveyed 
by a screw to a bucket elevator 0, which finally discharges it into the 
sand and metal separating apparatus P. In the latter mechanism still 
another conveyor Q is employed to transfer the rubber to the catch 
basin R. 



Devulcanizers. 

As early as 1855, Sigismond Beers took out a patent for an 
'^Improvement in Devulcanizing Kubber." While no illustrations were 
given, the process consisted in grinding the waste between rolls, then 
boiling it in an alkaline lye to extract the sidphur and devulcanizing 
by the use of turpentine and heat. 

Three years later Hiram Hall was granted a patent for ^'Restor- 
inii' Vulcanized Rubber" by first grinding the waste and then boiling 
in water for about 48 hours. He also described the use of sulphuric 
acid for ^'rotting the fabric." Xo description of the apparatus further 



308 



BUBBER MACHIXEBY 



than referring to ''cauldrons, kettles or tanks of any sort*" is given. In 
a later patent he mentions a closed vessel for use nnder steam pressure. 

The Eichaeds Devulcaxizee. 
In 1860. A. C. Richards patented the apparatus sho^^Ti in two 
views in Fig. 318. .1 is a horizontal iron cylinder supplied with steam 




^^^^mmmmM^^ 



Fig. 318. — The Richards Devulcaxizer. 

through a pipe B from a boiler C. A fire is built in the furnace B 
imder the devulcanizer, and the rubber heated to 600 deg. F. while the 
steam is being admitted. 

ATitchell's Fiest Devuecaxizee. 
Fig. 319 shows an apparatus patented by Mitchell in 1899. which 
discloses the art practically as it exists today. In describing his pro- 




Fig. 319. — Mitchell's First Devulcaxizer. 



RECLAIMING 



309 



cess, the inventor 



says, 



'I have discovered that 



great advantages 



are 



secured by heating the reclaiming agent and the rubber waste together 
in a closed vessel under pressure above the ordinary boiling or vaporiz- 
ing point of the solution employed as such agent." 

The apparatus was very simple, consisting of a heavy horizontal 
iron cylinder A, with a perforated steam pipe B leading in from the 
bottom. It was fitted also with a safety valve C and filling manhole D. 
At one end of the cylinder was the usual heavy cast iron door, although 
no means was fastening it were shown. 

The Mitchell Improved Devulcanizer. 

A year later Mitchell invented a far better devulcanizer, which 

is shown in Fig. 320. This consists of a long iron cylinder A about 

5 feet in diameter, with a track B inside, on which runs a car C. On 

the bottom of the cylinder are a series of heavy rakes D. These form 




Fig. 320. — The Mitchell Impro\t:d Devulcanizer. 

partitions and divide the waste and act like movable bins. In loading, 
a rake is put in position at the far end, the car is then run in and its 
load dumped upon the rake. This process is repeated until the cyl- 
inder is full. After devulcanization the rakes are pulled out one by 
one, thus removing the rubber. 



The Marks Devulcaxizer. 
In 1899, Arthur H. Marks patented a process of devulcanizing 
waste rubber by submerging the finely ground waste in a dilute alkaline 
solution in a sealed vessel, then heating the contents of the vessel to 
a temperature of 344 deg. F. and maintaining that temperature for 20 
hours. This apparatus was crude, and later Marks designed the 
apparatus shown in Fig. 321. Referring to the illustration. A is a 
horizontal steam-jacketed cylinder mounted on trunnions B and is 
slowly driven by belt pulley F. Steam is admitted to the jacket through 



310 



BUBBER MACHIXEBY 




Fig. 321. — The Marks Devulcaxizer. 

a pipe C and exhausts at D. There are two manholes E for filling and 
emptving. This is practically what is nsed for devnlcanization in all 
of the j)rocess factories. 

The Biggs Devllcaxizee. 
The Biggs rotary jacketed devnlcanizer, shown in Tig. 322. is a 
development of the one just described. It differs only in having several 




Fig. 322. — The Biggs Devulcaxizer. 



manholes instead of two. It is often fitted with agitators and nsed 
for extraction by chemical solntion. 

The Beaie Devulcaxizer. 
The devnlcanizer shown in Fig. 323 has a horizontal jacketed 
cylinder A which revolves in l}earings B, driven by a pinion and spur 
gear. The stirring blades E, attached to the center shaft, are stationary. 
while the blades F are attached to the cylinder and revolve with it. C 
is a steam pipe and D is a pipe for supplying water or caustic soda. 



RECLAIMING 



311 



There are two manholes for filling or discharging, and the steam jacket 
and inner cylinder have independent relief valves. 

The powdered wash is placed in the inner cylinder and treated 
with canstic alkali and water. Heat is then applied to the jacket and 




Fig. 323. 



Blair Devulcaxizer. 



the cylinder revolved. The stirring blades break up the rubber and 
make it plastic. It is then removed from the machine and washed and ' 
sheeted. 

The Price Peocess. 

In the Price process for alkaline recovery, the idea is to nse 
alkali so concentrated that the boiling point without pressure other than 
atmospheric is high enough to devulcanize. The first patent, in 1902, 
is for an apparatus consisting of a devulcanizer in which the waste is 
stirred by a spiral, while steam is admitted either to the jacket or to 
the interior. 

In another patent in 1904, Fig. 324, the apparatus consists of a 
tank A with a jacketed bottom B and a vertical shaft C having hori- 
zontal blades. The tank is fitted with a condenser I). The steam 
escapes at E, condenses in coils F and drips back, to keep the solution 
of constant strength. 

Somewhat in this line is the Peterson devulcanizer. This is hori- 
zontal, and has a jacket and a stirring arrangement consisting of 
revolving paddles. This was designed that pressure be applied to the 
alkaline solution, the steam devulcanization being accomplished by 
phenol and alkali. 

The Hellee Electric Devulcaxizer. 
Fig. 325 shows an apparatus for devulcanizing with the aid of an 
electric current. 



312 



RUBBER MACHINERY 




Fig. 324. — The Price Process. 



Ill the illnstratioii A is a cylindrical tank with a conical shaped 
bottom and contains a smaller, similarly shaped tank B. The upper 
ends of both tanks are closed by separate heads but have a common 
manhole and cover for filling. The space between these two vessels 
forms a heating chamber, which is supplied with steam through the 
inlet pipe C. In the lower end of the tank_5 is a funnel-shaped tank D, 
closed at its lower end by a valve F, which is operated by the lever G. 
Attached to its upper end is an open zinc cylinder insulated from D 
and connected to the electric battery L, The pipe H is attached to 
the outer tank and extends into the inner tank, one end terminating 
near the bottom of tank D and the other end being connected to the 
tank B by the opening I. A propeller J operated by a pulley on the 
shaft K forces circulation in the pipe H. 

In carrying out the process a sufficient quantity of ]')owdered waste 
is placed in the tank to cover the pipe H, the valve F being closed. The 
solution commonly used for each 100 pounds of rubber is 600 pounds 
of water, 21 pounds of sodium hydrate or potassium hydrate, and 
one pound of ferric sulphate. The material circulated through 



RECLAIMING 



313 



the pipe H by means of the propeller / and the electric current, 
and the steam heat acts upon the mass as it passes up through 
the inner tank and around the zinc cylinder. This process is con- 
tinued from 10 to 24 hours, after which the valve F is raised, 
allowing the solution to run down through the pipe M into the wash- 



ing cylinder i\^. 



This washing tank is filled with hot water to remove 




Fig. 325. — The Heller Electric Devulcanizer. 



the chemicals, especially the caustic alkalies. In order to assist in 
cleansing the rubber steam is introduced from the pipe surrounding 
the tank through the perforated pipes P. This a^'itates the solution 
and allows the rubber to sink to the bottom. The holloAv screened 
body Q is then lowered into the solution above the rubber so that the 
waste w^ater and chemicals are drained off through the pipe B. This 



314 RUBBER MACHIXERY 

washing process is repeated, fresh water being introcluced through the 
pipe y until all foreign materials are washed away from the rubber, 
after which the pure water and rubber are allowed to run out through 
the pipe S. , 

The Yaughx Watee Separator. 

Water remains in abundance in reclaimed rubber after treatment, 
and must be removed. Much of it is expressed mechanically, as in 
the Vaughn mechanical water separator, illustrated in Fig. 326. 

This machine consists of a tapered cylinder and screw of like 
shape, with ^xe screens fitted into the cylinder, three in the bottom 
half and two in the upper. Stock is fed in through a hopper on top 
and carried forward by the wings of the screw against a pressure cap at 
the opposite end. This pressure, together with the force applied from 
the screw, expels the moisture through the screens above referred to. 




Fig. 326. — The \"aughn Water Separator. 

The machine may run anywhere from 12 to 20 r. p. m.. though 
ordinarily it is run at 15. It is rather hard to state what capacity can 
be delivered on the Xo. 2, or large size, but we imagine between 600 
to 1.000 lbs. per hour, depending entirely upon the condition and 
grade of stock used. The amount of moisture removed will vary any- 
where from 50 to 70 per cent. As far as the load is concerned, the 
operation is continuous, as the machine is usually filled from a conveyor. 

Hot Air Dryer. 
As for heated dryers, the ordinary apparatus is a large, fiat, air- 
tight box with a wire screen near the top. on which a layer of the wet 
reclaimed stock is placed. A fan forces air through steam coils, where 
it is warmed. The heated air passes under the box and rises through 
the screens on which the rubber is placed and dries it. 



RECLAIMING 



315 



COXTI^^UOUS SCKEW PeESS. 

The American Process Press, shown in Fig. 327, is of the con- 
tinnous screw type and consists of a horizontal tapered screw built up 
on a hollow" perforated shaft through which steam is admitted to the 
material. The close fitting screw rotates inside a similarly tapered, 
slatted curb. The gradual decrease in size of the screw and its curbs 
causes the pressure. The material cannot turn with the screw and 
slip on the curb, and must move towards the small end as the screw 
turns. The press is fitted at its discharge end with an adjustable cone 
arrangement so that the discharge opening can be regulated to the con- 
dition of the material being pressed. By adjusting the cone any desired 
pressure is produced in the press. 




Fig. Z27. — Continuous Screw Press. 



Drainage is both internal and external. The lar^e drainage area 
offered by the spaces between the slats of the curb, supplemented by the 
drainage holes in shaft, insures complete separation of the liquids. At 
each end of the shaft is a special stuffing box, with a movable diaphragm 
and perforations in shaft, which permit the use of steam on a portion 
or all of the press. 

The material enters the feeder from a hopper and is mechanically 
measured, and forced into the straight portion of the screw. The 
screw carries it into the tapered curb and it is slowly and positively 
pressed. The material is continually fed in at one end and discharged 
at the other. The liquids are forced out between the slats and into 
drainage holes and are conducted to a tank. Generally, the pressed 
material falls into a screw or other conveyor and is carried away for 
subsequent treatment. 

Hot Am Rotaey Dryer. 

Fig. 328 shows the American Process steam-heated rotary dryer. 

It consists of a fan blow^er A, heating coils B and a cylindrical steel 

shell C. l^ear each end of the shell is a steel tire -D, which rests upon 

friction roller wheels E. These wheels are driven bv a chain belt and 



316 



RUBBER MACHIXERY 



sprocket wheel F on the shaft G. The drver is aligned so that the 
material moves gradually from the receiving end to the outlet. 

The wet material is fed through a hopper TI and comes in contact 
with the heated air from the steam coils. It falls to the bottom and is 
caught up by the ribs K and carried almost to the top of the cylinder, 




Fig. 328. — Hot Air Rotary Dryer. 



where it is again cascaded through the hot air to the bottom. This is 
repeated until the dry product is discharged from the opposite end of 
the cylinder. The motion toward the outlet is caused by the slope of 
the cylinder but it is also assisted by the strong draft of hot air which 
is forced through the dryer by the fan blower. 

The Cummer Deyee. 
A self-contained type of direct heat dryer is sho^\m in Fig. 329^ 
which illustrates the apparatus with a section of the steel casing cut 
away to show the interior of the cylinder. The wet charge is fed con- 
tinuously into the dryer through the feed spout A. The fan draws the 
heated air from the furnace through the hooded openings into the 




Fig. 329.— The Cummer Dryer. 



RECLAIMING 



317 



cylinder, wliicli revolves slowly. The lifting blades pick up and cas- 
cade the material through the heated air. As the charge travels through 
the cylinder the heat decreases and the moisture disappears from the 
material, until it is finally discharged at the end of the machine. 

RoTAEY Vacuum Deyees. 
The vacuum dryer is also largely used for drying reclaimed rubber. 
It is, briefly, a steam-jacketed cylinder, having heads fitted to each end. 
In it is a revolving tube for heating the interior, which also carries 
arms for agitating the material to be dried. The shaft for revolving 
this tube extends through a bearing in one cylinder head and has on 
the outside end a spur gear which meshes with a spur pinion on a 
countershaft underneath. On this shaft is a pair of tight and loose 
pulleys driven by belt from an overhead shaft. In the top of the dryer 
are two vertical loading apertures with removable covers. There is also 
an opening for the vacuum pipe, which connects with a condenser. In 




Fig. 330. — The Devine Rotary Dryer. 

the bottom of the drying cylinder are two or more openings with hinged 
doors for unloading. The operation is practically the same as for the 
crude rubber vacuum dryer. A rotary vacuum dryer 3 feet in diameter 
and 20 feet long will dry about 3,000 pounds of reclaimed rubber m 
ten hours. 

The Devixe Rotary Deyee. 
The dryer illustrated in Fig. 330 works under atmospheric pres- 
sure. It is a trough surrounded by a steam jacket, the former being 
covered by a sheet-iron dome fitted with vapor shaft and charging aper- 
ture. Within this trough rotates a tube drum, heated by live or exhaust 



318 



EUBBEB MACHIXERY 



steam with 1 Jades attached — or in some cases a shaft only with bhides 
attached — which elt'ect a continual sLiw turning over and heating of 
the niateriaL The drver is litted with a cijntinuous automatic charg- 
ing and discharging device. It can also l)e charged periodically. From 
1.2 to 1.3 pounds of steam is required to evaporate 1 pound of water 
out of the previously heated substance that is to be dried. 

Buffalo Vac uu^i Deyee. 
The dryer illustrated in Fig. 331 has a hollow steam-jacketed cyl- 
inder litted with heads at each end. In the center of the cylinder is a 
revolving heating tube, carrying arms and plates which eti'ect a tumlding 




Fig. 331. — Buffalo A'acuum Dryer. 

over or mixing of the material. In the top of the dryer are two aper- 
tures for loading and at the Ijottom two for unloading. The revolving 
parts are fitted with bronze bearings. It is operated in connection with a 
barometric surface condenser, depending on the amount of moisture or 
solvents being drawn from the material treated and whether or not it is 
desired to reclaim them. 

Steam is supplied to the jacket of the casing and to the inner 
revolving tube. The chamber between the center tube and the jacketed 



RECLAIMIISG 



319 



shell, after being loaded, is evacuated. This vacuum causes a rapid 
evaporation of the moisture and other solvents contained in the material. 
The vapors pass to the condenser, are condensed and either throw^n 
away or reclaimed. 

The Scott Deyee. 

Another dryer of the vacuum type is shown in Fig. 332. A is a 

cvlinder in which revolves a belt driven shaft B having concentric, 

spiral stirring blades C and D. The cylinder A is heated by the jacket 

L throuoh steam inlet M and exhaust N. The air is extracted from 




Fig. 332. — The Scott Dryer. 



the cylinder by the pump E through the air lines F and G and the 
condenser H. The receiver cylinder K collects, measures and drains 
off the moisture from the rubber. In this way the percentage of mois- 
ture is determined. 

The Stokes Dryek. 
Another rotary vacuum dryer is illustrated in Fig. 333. The 
cylinder is steam-jacketed and fitted with a shaft which is driven by 
a spur gear and pinion from a belt driven countershaft. Both the 
cylinder and drive gearing are mounted on the same frame. Fixed to 
the shaft inside the cylinder are two sets of spiral stirring blades. The 
inner set throws the material away from the center and distributes it 
evenly throughout the length of the cylinder, while the outer set draws 
the material towards the center, where the discharge outlet is located. 



320 



RUBBER MACHINERY 




Fig. 333.— The Stokes Dryer. 

A vacniim pump, condenser, dust collector, gage and steam connec- 
tions are part of the equipment. All joints and seams are electric 
welded. The bearings of the agitator shaft are adjustable so that the 
paddles can be raised and the bottom of the cylinder scraped clean. 

Cleaisting by Extrusion. 




Fig. 334.— The Cowen Strainer. 



RECLAIMING 



821 



The Cowen Steai]n^ek. 
Fig. 334 shows the Cowen device for cleaning devulcanized rnbber. 
It is similar to the ordinary tubing machine, and has a steam-jacketed 
casing A and a stock worm B driven by the gear C. At the front end 
of the cylinder is a thick plate D with large holes countersunk at the 
back to form seats to support small sieve discs E, one disc for each hole 
in the plate. Back of the plate D is a similar plate F containing sieve 
discs with larger perforations. The reclaimed rubber is fed into the 
hopper G and the stock worm carries it through the casmg where the 
heat softens it. It is then forced out through the strainers by the worm, 
metal and other foreigTi matter being retained by the sieves. Provision 
is made for removing the screens for cleaning. 

The Weir Straii^ee. 
Fig. 335 shows longitudinal and cross sections of a strainer, to 
be attached to the cylinder A of a tubing machine having the usual 




;0 O\0--Q..p_.0' 
|0 Q P O O O 

o o\6^ o o ©-^/^ 
o o io\o o o 
■o~T>>.a c? o o 

o o o^!p\ o o,- 

o o o <> \o j^ 

O O C3 C*, O yp 



c 



L7 



Fig. 335. — The Weir Strainer. 



stock worm B. The strainer consists of a hub C and a cap D, between 
which are placed a ring-shaped screen E and a circular screen F, both 
with a fine mesh. The hub and cap are perforated with larger holes G, 



322 



RUBBER MACHIXERY 



which taper ciitwardly to provide easy escape of the extruded rubber. 
The screen E is placed between the hub and cap to prevent it from 
coming in direct contact with the screw. Having the screen in the 
walls as well as in the end of the head provides a much greater strain- 
ing surface. 

RoYLE Theee-Way Head Steaixer. 

In Fig. 33(3 is shown a reclaiming strainer desigTied for heavy 

work. The body of the machine is supported on a broad, square base. 

It is chambered for heating or cooling, and accurately bored to receive 

the large and powerful stock worm driven by a belt and cut spur gear- 




FiG. 336. — RoYLE Three-Way Head Strainer. 

ing. The three-way head has heating or cooling chambers, and the 
holes in the plates are square instead of round. The usual wire gauze 
strainers can be removed for cleaning by unscrewing the octagonal 
headed bushings with the special socket wrench provided for that pur- 
pose. 

The Mitchell Sheetixg Mill. 
The final process in reclaiming is sheeting, and perhaps refining. 
This is done on ordinary or special mills similar to the standard rubber 
mixer. Of the special types that designed by Mitchell, and shown in 
Fig. 337, is of interest. 



RECLAIMING 



323 




Fig. 337.— The Mitchell Sheeting Mill. 

This mill has five rolls, A, B, C, D and E. K\\ are 16 inches in 
diameter except roll C, which is 18 inches. They are geared to run at 
the same surface speed, roll C running at 25 r. p. m. The four smaller 
rolls are adjusted by screws F. The reclaimed rubber is fed in between 
the upper rolls A and B and passes through the mill as shown, after 
which it falls dowm the inclined plate G. 

Refining. 
Refining reclaimed rubber consists in passing the sheeted stock 
through a set of smooth rolls set close together, producing a thin sheet. 




Fig. 338. — The Cable Refining Calender. 



324 



RUBBER MACHIXERY 



Often a boy scans the sheet and picks out impurities. The refiner 
itself forces many particles to the sides of the rolls and enables them 
to be more easily removed. Ordinary refining is done on two rolls. 

The Cable Reeiki^^g Calendek. 

A three-roll refining calender, which sheets and refines at the 
same time, is shown in Fig. 338. The rolls A, B and C are mounted 
in the standards D of the frames, the middle roll B in fixed bearings, 
while the rolls A and C are adjustable vertically. The plastic mass of 
rubber E is spread uniformly over the surface of the roll B and passes 
before the workman, who removes the impurities. The rolls B and C 
are set about twice as far apart as rolls A and B, and are geared together 
i-o that the lower roll revolves -with about half the surface speed of the 
other. This difference in speed causes the rubber sheet G to part from 
the middle roll and move down on the opposite side of the slow roll C. In 
consequence the soft rubber sheet substantially doubles in thickness. 

Back of the lower roll C is the small delivery roll H revolving at 
a surface speed faster than roll C driven by a friction wheel /. This 
receives the thickened sheet G from the roll C and deposits it on the 
platform in layers for further treatment. 

Reclaimed Rubbek Press. 
The press illustrated in Fig. 339 is used for pressing reclaimed 




Fig. 339. — Reclaimed Rubber Press. 



RECLAIMING 



325 



rubber into slabs. It is operated by livdraiilic pressure through an 
accumulator or from a single pump installation. The apparatus is of 
the upward pressure type, the ram having a working pressure of 1,000 
pounds, with a travel of 13 inches. A track running through the press 
between the frame members carries two steel mold boxes which receive 
the rubber and carry it into the press. One box is always in position for 
unloading and refilling while the other is under pressure. One side and 
end of each mold box are provided with hinges which permit the boxes 
to be opened for removal of the pressed rubber. The pressure head is 
machined to fit the boxes, which are 22 inches wide, 26 inches long 
and 13 inches deep. When pressure is applied, the box with the rubber 
is forced upward and over the pressure head, and the rubber is pressed 
into a slab in the bottom of the box. The machine is fitted with the 
usual hydraulic gages and valves for controlling and registering the 
pressure. The apparatus is constructed of steel throughout, which 
adapts it for long and hard service. 

The Reforming of Rubbek Waste. 
By reforming is meant the remolding and revulcanizing of ground 
vulcanized scrap without reclaiming. A few years ago in England 




Fig. 340. — The Havward Reforming ]\Iold. 



this subject attracted much attention. It was not altogether new, how- 
ever, for in 1854 Daniel Hayward patented a reforming process. 



326 



BUBBEB MACHIXEBY 



The Hayward Refokmixg Mold. 
This device is shown in Fig. 340, as applied to the maunfactiire 
of rubber buckets. Both the inner die A and the outer mold B are 
cored for steam or water as required. By a hand screw C pressure 
is brought to bear upon the rubber in the mold space D. 

The Gaee Peocess. 
In 1910. Gare. an Englishman, took out manv patents for a pro- 
cess analogous to Hayward's. but which went much farther. The Gare 
process consisted in taking waste rubber and gTinding it bv special 
grinders into a line powder. Afterward this was placed in a cold 
mold : then pressure was applied to expel the air. Finally the mold and 
powdered ruljber waste were heated to a temperature of about -100 
deff. F. 




Fig. 341. — The Gare Reforming ^Machine. 

The difference between the above methods and those (except the 
high temperature ) known to rubber manufacturers will not be apparent 
at first sight : Ijut there is one difference — the applying of pressure to 
the mold before the application of heat. Gare heated the waste rubber 
far above the vulcanizing temperature — i. e.. -100 to 450 deg. F. The 
effect of the intense heat during the process, so Gare claimed, was to 
accomplish the perfect mechanical fusion of the particles of powdered 
vulcanized waste rubber. 



The GaPvE Eefoemixg Machixe. 
In the manufacture of cab tires. Gare's process was in general th^ 
same as that described above. One form of machine used is shoAvn in 
Fig. 341. Referring to the drawing the powdered stock is fed through 
a hopper .1, and the stock worm B compresses and forces it into the 
mold. The air escapes throug'h holes C in the casing or through the 
hollow shaft of the screw. The stock, heated by a steam jacket D. 
passes through the mold part E. where it is shaped and vulcanized and 
is cooled as it passes out through the part F. 



CHAPTER XIX. 

TEMPEKATUEE KECOKDHSTG AND CO]^TEOLLING 

DEVICES. 

A GREAT variety of instruments for recording and controlling 
temperature and pressure during vulcanization are in use, and 
their importance can hardly be overestimated. The thermometer, 
or steam gage in some form, is always present, always necessary. I^ot 
only are the various devices important but the manner of application is 
of moment. ^N'one of the controlling devices, for example, are effective 
unless the vulcanizer or press produces even cures. Over-taxing the 
capacity of the main steam line is often supplemented with other faulty 
piping and will result in uneven cures. In many cases a long vulcan- 
izer is supplied with steam from one connection, usually at the head. 
This cannot insure uniform heating, as the end nearest the steam inlet 
heats first. 

x\ll long vulcanizers should be provided with three or four inlets, 
spaced to insure rapid and uniform distribution of the steam. Yulcan- 
izers are rarely provided with blow-oif s on the upper side ; consequently 
air is trapped, and irregular curing results. The best way is to pro- 
vide a large exhaust and open it wide, to be closed when the steam 
escapes in good volume. This will drive out all air, and c^use the 
steam to circulate uniformly. 

Steam with water in suspension is not as hot as dry steam and 
retards the cure. To cure in dry steam, three factors are required, — 
dry incoming steam, rapidity of circulation and quick discharge of the 
wet steam and condensation. 

When steam is turned into a large vulcanizer, the condensation is 
rapid. This should be discharged rapidly, to equalize the heat ; thero 
fore it is necessary to open the discharge valve wide. When the steam 
leaves the discharge pipe bluish in color, condensation has ceased and 
the discharge valves can then be throttled to permit the water to pass 
out freely ; or a good trap can be used to advantage. 

Where pressure gages only are used in vulcanizing, it is not un- 
usual to find no two gages indicating alike. This is easily accounted for, 
since Bourdon springs cannot retain their accuracy any length of time 
and must be often tested and adjusted. Steam control of a vulcanizer 



328 EUBBEE MACHIXERY 

or press should always be done by temperature observation alung witli 
pressure recording. 

When gages alone are used they may be misleading- for should 
the platens till Avith Avater the gage aauII not indicate the fact. Eecord- 
ing thermometers or gages are most desirable adjuncts, as thcA' giA^e a 
true record of conditions. The hand control of a Auilcanizer or press 
is accomplished by throttling the steam YRlve. If the steam pressure 
Avas ahvays uniform the A-ah-e might be so nicely throttled that the 
temperature could be maintained AAuthout appreciable A^ariation. but it 
A'aries. and the A^ah^e must be constantly turned. That is AA^hy pressure 
governors and automatic regulators are used in so many of the larger 
works. 

The proper placing of the thermometer also merits careful con- 
sideration. The bulb should not project inside a vulcanizer far enough 
to be struck and liroken. It should be enclosed in a special fitting, 
provideil Avith a vent cock. AA^hich should be Avide open Avhen steam is 
turned on and afterAvards throttled so that just sufficient steam escapes 
to keep up a good circulation around the thermometer bulb. Instead 
of the special fitting, a nipple and tee can l>e used Avith the Ax^nt cock 
or valve scroAA'ed in the side outlet of the tee. 

On presses, the thermometers being on the side, it is often impos- 
sible to screAv them directly into the platens. It is therefore necessary 
to use the special fitting. Sometimes a nipple Avith a coupling is 
scroAved into the top of the vulcanizer or side of the press and the ther- 
mometer scroAved into it. Such arrangement is bad. The thermometer 
cannot indicate the true temperature, as air pockets in the fitting and 
steam cannot circulate freely aroimd the bull:*. Thermometers are often 
used Avhere small particles of mercury are lodged in the tul">e above 
the main column. This creates an error, and should be corrected as 
soon as observed. On long vulcanizers it is desirable to haA^e tAvo or 
three thermometers in order to note the temperatures in difi'erent parts. 
A thermometer near the door is not Avell placed, because the radiation 
of heat by the uncovered door loAvers the temperature. On lono- presses 
it is ilesirable to have tAvo or three thermometers on each of the platens. 

PeESSUEE REOrLATOES. 

T\Tien steam at a loAver pressure than that carried on the boilers 
is used, it is necessary to employ some t^-j^e of regidating valve to main- 
tain a constant pressure and temperature. A number of such valves 
are manufactured, several of Avhich are illustrated liereAAuth. 



RECORDING AXD COXTROLLIXG DEVICES 



329 



The Masox Reducixg Yalve. 
Fig. 342 illustrates the Mason reducing valve, designed to auto- 
matically maintain an even reduced steam pressure regardless of the 
variation of the initial boiler pressure. In operation, the valve is con- 
trolled by the variation of the reduced pressure acting through the 
port A J on the diaphragm B, which is resisted by spring C that is 
adjustable to the desired reduced pressure. The diaphragm will rise 
with an increase of the reduced pressure and is forced down by the 




Fig. 342. — The AIasox Reducing \'alve. 

spring C when the reduced pressure is decreased. As the diaphragm 
is balanced between these two forces, any slight change of reduced pres- 
sure will cause a movement of the diaphragm. 

An auxiliary valve D, held in contact with the diaphragm by the 
small auxiliary spring E, moves up and down with the diaphragm. 
When the valve D is open, steam passes through the port F and under the 



330 



RUBBER MACHINERY 



piston G. This opens the main valve H against the initial pressure 
and steam is admitted to the system. 

When the pressure has reached the required point — which is deter- 
mined by the main spring C — the diaphragm is forced upward by the 
low pressure w^hich passes up through the port A, thus permitting the 
valve D to close and shut off steam from the piston G. The main valve 
is then forced to its seat by the initial pressure, shutting off steam from 
the system and pushing the piston G to the bottom of its stroke. 

In practice the main valve does not open or close entirely with each 
slight change of pressure but assumes a position to supply just the 
amount of steam to maintain the desired pressure. 

The AVatsox-McDaxiel Valve. 
A different type of reducing valve is shown in Fig. 343. It is 
only necessary to set the weight A on the lever 5 at a point where the 
steam gage indicates the desired pressure. Steam enters the valve body 




Fig. 343. — The Watson-McDaniel Valve. 

at C and passes through small holes into the hollow piston D, then 
out of the valve at E and into the system. When the pressure on the 
low-pressure side becomes great enough to overcome the force exerted 
by the weight and lever, the steam forces the piston up and closes the 
holes or ports. The valve adjusts itself to feed just enough steam to keep 
the required pressure in the system, the variation in boiler pressure not 
affecting its operation, because the valve is controlled by the steam on 
the low-pressure side. 



The H. axd M. Peessvee Regulatoe. 
The principle of operation of this controller is the counter-balance 
of steam pressure by weight. It is operated by compressed air. Refer- 
ring to Fig. 344, the regulator is attached to the vulcanizer by the 



RECORDING AND CONTROLLING DEVICES 



331 



union A so that there will always be a water seal under the diaphragm 
B. The steam enters the valve M through the end marked ''inlet/' 
The union C is connected to the air pressure supply. By manipulation 
of the sliding weights D and E on the lever arm F, and the addition 
of weights placed on the hanger G, any desired pressure can be obtained. 
The weights are all marked in pounds and the lever arm is graduated. 
When the regulator is set at the desired temperature, air pressure is 
turned on, and steam is admitted at A. As soon as the temperature 
in the vulcanizer rises beyond the desired point, the pressure on the dia- 



STEAM 
INLET 




Fig. 344.— The H. & M. Pressure Regulator. 



phragm B overcomes the weight on the lever arm F, closing the valve / 
and opening the valve /. This allows the air pressure from C to enter 
the diaphragm chamber, inflating the diaphragm L and shutting off the 
steam in the supply valve M. As soon as the temperature drops, the 
w^eights on the lever arm overcome the pressure on the diaphragm B. 
This is forced back in place, cutting off the air supply, which allows 
the valve M to open and steam again enters the vulcanizer. In actual 
working conditions this regulator is so sensitive that the steam is throt- 
tling all the time. 



332 



RUBBER MACHINERY 



The Squiees Valve. 
In some types of reducing valves the main valve is operated by the 
initial pressure. Fig. 345 illustrates a valve which is controlled by a 
pilot valve A, and governed by the low-pressure side. The pilot valve 
is piped to the high-pressure side of the shut-off valve in the steam line 
of wdiich the pressure is to be reduced. The outlet B at the top of the 
pilot valve is connected to the reduced pressure side. 




i-"i<:. .U5, — Till-; SoriuKS Valve. 



In operation, the reduced pressure, acting on the diaphragm C of 
the pilot valve, is balanced by the tension of the spring D, which ten- 
sion is adjusted by the nut E. When the reduced pressure overcomes 
the spring, the pilot valve will seat and steam will seep past the resis- 
tance plug F, thus increasing the pressure on the main diaphragm G and 
decreasing the main valve opening. If the reduced pressure is overcome 
by the spring, the pilot valve will lift from its seat, opening the exhaust 
port H to the atmosphere. The pressure is then reduced on the main 
diaphrag-m and the main valve will open, allowing more steam to enter 
to the reduced-pressure side of the valve. The continuous opening and 
closing of the main valve maintains the reduced pressure for which the 
valve is set. 



RECORDIXG AND CONTROLLING DEVICES 



333 



The Davis Regulatoe. 
The regulator shown in Fig. 346 is designed for the reduction of 
steam from any initial pressure to anv delivery pressure. Steam enters 
the high-pressure chamber and, in passing through the seats into the 
cylinder, tends to force the piston upward and close the inner valve to 
which it is attached by a link. This tendency, however, is counteracted 
by weights suspended from the lever which is connected to the piston 
by a yoke and stem. Thus a balance between the steam pressure and 
the weio'ht is attained. 




Fig. 346. — The Davis Regulator. 



If the delivery pressure increases it forces the piston up, and the 
inner valve closes somewhat and throttles the pressure until a balance 
is again reached. If the delivery pressure decreases, the weights carry 
the piston dowai and the inner valve will open wider: the pressure 
under the piston, therefore, increases until it again balances the weights. 
This repeated action maintains a constant delivery pressure, which is 
increased or decreased bv addino^ or removina; w^eisrhts. 



334 



RUBBER MACHINERY 



The Saeco Thekmostatic REorLATOE. 

The regulator illustrated in Fig. 347 operates on the thermostatic 
principle, using as its motive power the expansion of a sensitive liquid 
hermetically sealed within a chamber into which is inserted a flexible 
corrugated tube. 

The regulator is made up of the thermostatic element A, which is 
inserted in the vulcanizer, the controller element B and the valve C. 




YiG. 347._The Sarco Thermostatic Regulator. 

The element A contains a heavy hydrocarbon oil, into which is 
inserted a piece of crimped copper tubing D, the length of which is 
extended or reduced by turning the regulator head E. From this ther- 
mostatic element a piece of fine copper tubing E runs to the controller 
B, which also contains a crimped copper tube G capable of compression 
when an increased temperature causes the liquid in the tube A to 
expand. 

When the temperature increases in the vulcanizer into which the 
tube A is inserted, the pressure in the tube increases and is transmitted 



RECORDING AND CONTROLLING DEVICES 



335 



to B, causing a compression of the tube G, which forces the piston H 
down and tends to close the valve C. The springs / and / operate in 
the opposite direction and tend to keep the valve open, which action 
is accomplished as soon as the pressure and temperature in the vulcan- 
izer are reduced. Any change in pressure, and consequently any tem- 
perature change, tends to either open or close the valve C, thus keeping 
temperature constant. 

The Atwood & Moerii.l Kegulatoe. 
The combination regulator shown in Fig. 348 is controlled by 
steam and water pressure. A is a cord that runs from the w^eighted 
piston rod E and is attached to the lever B of the valve C in the steam 




Fig. 348. — The Atwood & Morrill Regulator. 

supply pipe D. When the piston E is in the position shown the valve 
C is open. As soon as the pressure in the discharge end of the steam 
pipe D reaches a predetermined point the pressure is exerted through 
pipe K on the diaphragm of the regulator in the casing F. This torces 
up the weighted lever G, which in turn operates the water valve ll, 
admitting water pressure into the cylinder I. The water pressure 
forces the piston E up, which permits the weight J to close the valve C, 
shutting off the supply of steam. 

When the pressure in the pipe D is reduced the weighted lever G 
overcomes the pressure exerted against the diaphragTQ in F and assumes 



336 



RUBBER MACHINERY 



a lower position. The water ralve II is brought to the discharge posi- 
tion and the water pressure in the cylinder 1 is released. The weights 
E force the piston down, which opens the valve C and allows more 
steam to enter the pipe D. 

Steam Gages. 
The purpose of a steam gage is to indicate the pressure in pounds 
per square inch by an index and a graduated dial. 



Fig. 349 shows two views of the ordinary 



American Peessuke Gage. 

type, in which A is an 
elliptical metal tube connected at one end to a steam pipe B and at the 
other end with levers and gearing C. The greatest breadth of section 
of the Bourdon tube A is perpendicular to the plane in which it is 
curved. When the pressure inside the tube, which is filled Avith water, 
is greater than the external pressure, it tends to straighten, causing the 




Fig. 349, — American Pressure Gage. 



sector to move the index D. This indicates the pressure on the gradu- 
ated dial E. An inverted siphon pipe is usually placed below the gage, 
its object being to contain water and thus prevent the heat of the steam 
from injuring the mechanism of the gage or distorting its action by 
expansion. 

A steam gage is apt to get out of order in consequence of water 
lodging in the end of the tube and corroding it. Consequently, it 
should be tested frequently, either by a gage known to be correct or by 
a testing machine. Steam should never be allowed to act directly on a 
steam gage, and when exposed to the cold it is liable to freeze. The 
ordinary steam gage registers pressures above that of the atmosphere, 
the total pressure being measured from a perfect vacuum, which will 
add 14.7 pounds in the average to the pressure shown on the steam 
gage. 



RECOBDIXG AXD COXTEOLLIXG DEVICES 



337 



VAcruM Gages. 
Gages are also used for indicating the amount of vacuum in a 
vessel. 

The Tagltabue VAOur^r Gage. 
The aaae illustrated in Fie;. 350 indicates re^^ardless of the state 
of the barometer. The scale is so graduated that adjustment for the 
varvino; level of mercurv in the svstem is not necessarv. 




Fig. 350. — The Tagliabue Yacutm Gage. 



The glass tube is sealed at the top and open at the bottom. It is 
filled with mercurv, which is then boiled. The glass is protected by a 
scale case A. The lower end is open and extends into a mercury well 
B %-inch from the bottom. It has a stuffing-box and the end of the 
glass tube is always surrounded by mercury. The well B and level 
chamber D are connected by a channel, the level chamber being filled 
with mercurv to the zero deo'ree of the scale. The ffa^'e is flanged at 
G for connecting to the vessel in which the vacuum is to be maintained. 



338 



RUBBER MACHINERY 



When a vaciiimi is applied to the gage the mercury will drop in 
the tube, due to the absolute vacuum in it. and as the top of the tube is 
sealed, no air can enter. Barometric changes will not affect the accur- 
acy of the gage. 

Recordixg Gages. 
It is often desirable to have a record of the steam pressure or 
vacuum carried in a vessel. The steam or vacuum gage will indicate 
the pressure or vacuum carried at the time of reading but keeps no 
record of their performance. A recording instrument will trace on a 
revolving chart, by means of a pen, the pressure carried for a period 
of 24 hours, when a new chart is placed on the dial. These charts are 
saved for reference and show the pressure carried at any time during 
the 24 hours. 

The Beistol Kecoedi]N"g Gages. 
The illustration, Fig. 351, shows the original form of the record- 
ing pressure and vacuum gages made by the Bristol company. In the 





Fig. 351. — The Bristol Recording Gage. 

center is the pressure gage with switch board form of outer casing com- 
mon to both the pressure and vacuum gage. The charts and operating 
mechanism, however, are different. On the left is shown the mechan- 
ism of the gage. It is for recording high pressures up to 12,000 pounds 
per square inch, used for steam, air, gases or liquids, and made to read 
in pounds, ounces, inches, feet, metric or any desired units. The 
recording arm is attached directly to the moving element, which con- 
sists of a helical tube with several convolutions, giving ample motion 
without overstraining. The chart is moved by a reliable clock move- 
ment. 



RECORDING AND COXTROLLIXG DEVICES 



339 



On the right is shown the mechanism of the low pressnre vacunm 
o-age for total ranges from fnll vacuum to 6/10-inch of w^ater. The 
even scale chart, operated by a special clock movement, is graduated for 
range of to 30 inches of mercury or full vacuum. The diaphragm 
tvpes of pressure tubes are used, to which the recording arm is directly 
attached. 

Peecisiox Recoeder. 

Fig. 352 shows a recorder which uses a Bourdon tube for high 
pressures. For low ranges the conditions of pressure are transmitted 




Fig. 352. — Precision Recorder. 



by flexible diaphragms A. These consist of two strata of metal of 
equal expansion, one used for its elasticity and the other for its ability 
to resist corrosion and the action of acids. The pressure is transmitted 
from these diaphragms or chambers A to the pen B by an arrangement 
of levers, so adjusted that a correct record is obtained over any part 
of the chart. The instrument is made to register either pressure or 
vacuum. 

Peecisiox Coxtixuous Recoedee. 
A continuous recorder is shown in Fig. 353. The system of trans- 
mitting the pressure is the same as used in the preceding instrument, 



340 



BUBBEB MACHIXEB 




Fig. Z3i. — Precision Continuous Recorder. 



but there is a difference in the method of recording. The record is 
not made on a chart that reejuires changing everv 24 honrs, but npon 
a roll of chart paper which can be torn off* at any desired intervals, the 
roll lasting 60 days. The record is always visible. 

RecopvDixg axd Alae:^! Gages. 
Several styles of pressure recording and alarm gages are made. 

The Eds ox GaCtE. 
This is shown in Fig. 354. It is suitable for use with steam, water 
or any other liquid except ammonia. The gage is connected to an 
electric bell which sounds an alarm when a predetermined high or low 
pressure is reached. The recorder has a chart speed of one-half to one 
inch per hour. The gage can be had for recording vacuum or for 
recording both pressure and vacuum. 

The Ideal Gage. 
An alarm gage designed for pressure or vacuum is shown in Fig. 
355. Combined with the gage is an automatic electric circuit-closing 



RECORDIXG AXD COXTROLLIXG DEVICES 341 



Ml 





Fig. 354.— The EdsoxN Gage. 




Fig. 355.— The "Ideal'' Gage. 



342 



RUBBER MACHIXERY 



attachment, which rings a bell at anv desired pressnre and at any dis- 
tance from the gage. 

Thee^iometees. 
As steam at various pressures alwavs has a corresponding tempera- 
ture a thermometer may be used to determine the pressure in a vessel. 
For instance, steam at a pressure of 100 pounds above vacuum has a 
temperature of 327.6 degrees F. ; at 150 pounds, a temperature of 358. 2 
degrees, and at atmospheric pressure, or 14.69 pomids absolute, it is 
212 degrees. Knowing the steam pressure desired and the correspond- 
ing temperature, the thermometer can be used to designate the pressure 
being carried. 




Fig. 356.— The H. & U. Thermometers. 



Thermometers are used for l)oth low and high range. The former 
ranges from 20 degrees F. below to around 220 degrees above zero; the 
latter from zero to 1,000 degrees F. Thermometers for use with steam 
are usually made with a temperature and pressure scale as shown. 



RECORDING AXD CONTROLLING DEVICES 



343 



The straight thermometer shown on the right in Fig. 356 has a 
separable socket connection and a 12-inch scale with a range 200 to 
340 degrees F. and to 100 pounds pressure. It is used on open 
steam vulcanizers, tire and belt presses. On the left is the right side 
angle thermometer with separable socket connection. It has the same 
scale and range as the vertical thermometer and is used on mechanical 
goods presses. It is convenientlv attached to the side of the platen 
and the face can be turned at any angle. A small fitting called an ele- 
vator or steam circulating pocket is sometimes attached to the ther- 
mometer for insuring circulation of drv steam around the bull). 

Mercury Cup Ther:\iometer. 
If the pressure is low, the thermometer socket is screwed into the 
vessel or the steam pipe. A steel cup A is frequently screwed into the 
pipe and then partly filled with mercury. Fig. 357. Wheu the tempera- 
ture is to be taken the thermometer B is inserted and as the mercurv 




Fig. 357.— Mercury Cup Thermometer. 



344 



BUBBER MACHIXEBY 



is CI the same temperature as the steam, a correct reading is obtained. 

A plug C, screwed into the cup when not in use. keeps the mercury 

clean. The thermometer may also be permanently secured in the cup. 



The H. »!^ M. Vaexish Theemometek. 
The use of thermometers in the manufacture of shoe varnishes 
has become practicable, with instruments capable of indicating reliably. 
temperatures ranging from 600 to 1.000 degTces F. 




Fig. 358.— The H. & M. 



RXI^H THESMOilETER. 



It is a well known fact that mercury boils at about 676 degrees F. 
im.der atmospheric pressure, but when containel in an ordinary glass 
thermometer tube which is vacuum above the colunm. ebidlition takes 
place at a lower degree of heat. For this reason ordinary thermome- 
ters cannot be used in giini melting, although the scale may indicate 
much higher than the capacity of the thermometer. 

T(3 obtain a thermometer capable of indicating temi)eratures above 
the boiling point of mercury, it is necessary to replace the vacuum 
above the column by pressure; in other words, hlling the space with 
a compressible gas. which, according to the degTee the thermometer is 
intended to register, must be compressed at ordinary temperatures. 

The long stem thermometer shown in Fig. 358 is of this type and 
is used in manufacturing rubber boot and shoe varnishes. They are 
all made with sliding scales and a scale adjusting device is furnished 
on order. 

The Bkistol Recoedixg Theemometee.s. 

As in the case of pressure gages, thermometers are made to record 
the temperature for each 24-hour duration. Recording thermometers, 
for example, are made for low and high range. Both depend for their 
operation on the expansion of a gas contained in a bulb, which is con- 
nected by a flexible capillary copper tubing to either a helical or spiral 
form of pressure tube. Any change in temperature at the bulb causes 
a change in the pressure of the gas contained in it. This change in 
pressure is transmitted through the flexible capillary tube to the pres- 
sure tube in the thermometer. The recording arm is attached to the 
pressure tube and records the temperature on the round chart of the 
instrument. 



RECORDIXG AXD CONTROLLING DEVICES 345 

The Beistol Bulb Attached to Pipe Elbow. 
Fig. 359 shows the recording thermometer bulb for measuring the 
temperature of liquids, steam, gas and air in pipes under pressure. 




Fig. 359. — The Bristol Bulb Attached to Pipe Elbow. 

The Bristol Bulb with Socket. 
In Fig. 360 the bulb is shown protected by a socket. This is 
necessary with superheated steam, condensed w^ater, compressed air and 
similar applications where the bulb is liable to be injured. 



^^amj^^ 



I 



Fig. 360. — The Bristol Bulb with Socket. 

The Bristol Helical Tube Becordee. 
The mechanism of this recording device is shown in Fig. 361. 
Changes of temperature at the sensitive bulb cause corresponding 
changes in the pressure of the gas inside the bulb, and these changes 
are transmitted through the flexible capillary connecting tube to the 
helical pressure tube in the recording instrument. The recording pen 
arm is attached directly to the pressure tube without the use of any 
multiplying devices, gears, links, levers or other complicated mechanism. 

The Bristol Spieal Tube Recoeder. 
The thermometer shown in Fig. 362 has the spiral form of pres- 
sure tube and is used for the higher ranges of temperature, such as 
800 or 600 degrees. It has also recently been adapted for the low 
ranges of temperature, such as atmospheric ranges and refrigeration 
temperatures. In order to adapt these thermometers for accurately 
recording low ranges of temperature a special compensating attachment 
makes these thermometers independent of changes of temperature at the 



346 



RUBBER MACHINERY 





Fig. 361. — Hellical Recorder. 



Fig. 362. — Spiral Tube Recorder. 



recording instrunieiit. Xo multiply iiig devices are eiiiploved. The 
pen arm is attached direct to the double pressure tube. 

The recording thermometer, as in the case of the recording gage, 
produces an undisputed record of the steam pressure and the tempera- 
ture carried in the vulcanizer. If the goods are not right when removed 
and if the fault is due to the temperature, the chart indicates where 
to look for the difficulty and whom to hold responsible. 

The recorder may be placed at a distance of 25 feet from the bulb 
and thus is easily placed in the foreman's office where the record pro- 
duced may be under his observation at all times. A chart from a 
recordino- thermometer is shown in Fia:. 363. 



Tempeeatuee Aeaem System. 
An early system of temperature regulation, Fig. 364, consisted of 
a therinostat, a butterfly steam valve, batteries and a motor. The ther- 
m-ostat A fitted with three contacts is attached to the vulcanizer B. The 
central wire is attached to the outside terminal of the motor C. The 
other outside motor wire connects with the battery D and the central 
motor terminal connects with the outside terminal of the thermostat, 
the other thermostat terminal beino^ connected with the batterv. 



BECORDIXG AND CONTROLLING DEVICES 



347 




Fig. 363. — Chart Made by Recording Thermometer. 




Fig. 364. — Temperature Alarm System. 



With a low steam pressure and temperature the contact is made 
between two terminals of the thermostat, causing the motor to operate 
in a direction to tighten the cord E and lift the weighted lever F of 
the valve G. This action admits steam into the vulcanizer through the 
.steam pipe H. When the temperature reaches a certain high limit, 



348 



RUBBER MACHINERY 



contact i. made with the other thermostatic terminal, reversinii^ the 
motor, which loosens the cord E. The weight then closes the valve G, 
shutting c-i' the steam supply. Besides the thermostat, the vulcanizer 
IS fitted with a steam gage / and thermometer J . 

Electric Alaem System. 
An electric alarm regulator capable of attaching to a vulcanizer is 
illustrated in Fig. 3(35, its purpose being to signal to distant points the 
degrees of temperature. The thermometer A is attached to the vul- 
canizer B. Electric connections C, D and E from the mercury 
column in the thermometer connect with the l)atteries F . switch G 
and the bells H and /. The electric circuit is affected by the rise and 
fall of the mercurv column. The center connection E is at the 140- 



ram 

r 




iT^ 



Fig. 365. — Electric Alarm System. 



degree graduation, corresponding to about three pounds pressure above 
vacuum, and connects wuth the bell /. When the temperature in the 
vulcanizer reaches 140 degrees, the mercury contacts with the wire E, 
forming a circuit through the mercury column, wire C , batteries F, 
switch G , bell I and wire E to the mercury, thus completing the cir- 
cuit and ringing the bell I. "When this bell rings and it is desired 
to increase the temperature to 180 degrees, the switch is thrown to the 
position shown by the dotted lines. Then, when the mercury column 
reaches the ISO-degree graduation, corresponding to about 8 pounds 
pressure above vacuum, a circuit is formed through the wire D, bell 
H, switch G, batteries F and wire C to the mercury column, thus com- 
pleting the circuit and ringing the bell H. 



RECORDIXG AXD COXTROLLIXG DEVICES 



349 




350 



RUBBER MACHINERY 



The Tagliabue System of Tempekatuee CoxtPvOl. 

The leading feature of this system is the pressure governor for 
throttling the steam valve, in accordance with the pressures inside of 
the vulcanizer or press. 

When the governor is set for the desired temperature or pressure 
and the steam turned on, the heater practically takes care of itself. As 
there is a definite equivalent in degrees of temperature for every pound 
of pressure of saturated steam, weights for the governor give control 
at any desired degree of heat, and as all the observations are made 
with the thermometer, it is virtually temperature control. 

The apparatus shuts off the steam at the expiration of the cure, 
and if desired also operates a blow-off valve. 

Fig. 366 illustrates the arrangement of the system as applied 
to a vulcanizer. Compressed air is used for operating the controlling 
valves. The air compressing outfit consists of a small steam air com- 
pressor A^ and air storage tank A, mounted on a stand. The tank is 
supplied with pressure gage, and from the top is taken the main air 
supply line A^, subdividing into the branch lines .4% supplying the 
pressure governor B and the time device C. The air pressure required 
is 15 pounds or more. To maintain this pressure constant the con- 
trolling valve A- is placed on the steam line to the compressor, and 
connected to the storage tank. This valve can be adjusted for any 
required air pressure, and will control the supply of steam to the com- 
pressor, so that the desired pressure of air will be maintained with a 
minimum use of steam. As the amount of air used by each device is 
small, this compressor will furnish air for quite a number of vulcan- 
izers. The air intake to the compressor is placed out of doors, away 
from steam vapor or dust. In the bottom of the storage tank is a 
blow-off valve, A^, for blowing off at intervals accumulated water and 
oil. 

The pressure governor B is provided with a flange for securing it 
to the wall near the vulcanizer or press. The lever is hung on knife 
edges and is as accurate as a scale beam, as it rests on a rubber dia- 
phragm in the circular base. Above the lever is a circular casing, con- 
taining the air valves operated by the lever. The base containing 
the diaphragm is connected to the vulcanizer or press by means of 
pipe B-. To the top is connected the air supply pipe A^ and the air 
discharge pipe A^, which latter is connected to diaphragTii valve B^. 

The diaphragm valve B^ is placed on the steam line to the vul- 
canizer and is of the globe type. On the bonnet is screwed a cast iron 
frame, in the top of which is secured a rubber diaphragm. The stem 



RECOBDIXG AXD COXTROLLIXG DEVICES 351 

of the valve is sliding, surrounded by a volute spring, and topped with 
a wooden saucer, resting against the rubber diaphragm. When the 
latter is actuated it presses against the saucer, which forces down the 
sliding stem, compresses the spring and closes the valve. When the air 
discharges, the diaphragm collapses, the steam pressure under the seat of 
the valve, by the aid of the spring, forces back the stem, and opens the 
valve.. 

The pressure governor operates thus : A weight equivalent to the 
pressure denoting the temperature desired, is placed on the hanger at 
the end of the lever. Cock B'^ admitting compressed air to the governor 
is opened, and steam turned into the vulcanizer or press at the hand 
valve D-. This is communicated to the diaphragm of the governor, 
through the pipe B'-, and when* the desired pressure has been reached, 
the diaphragm actuates the lever, which in turn operates the air inlet 
valve in the upper casing B, permitting the passage of air into the pipe 
A\ compressing the diaphragTii in steam valve B^", forcing down the stem 
and shutting off the steam. When the pressure falls the fractional part 
of a pound, the governor diaphragm collapses slightly, lowers the lever, 
closing the air inlet valve, and at the same time opening an air dis- 
charge valve, which relieves the steam valve diaphragm of the air 
pressure causing it to collapse, and permitting the steam valve to open 
again. During the vulcanizing process the diaphragm steam valve B'^ 
is rarely wide open or fully closed, for the reason that the governor 
is so sensitive that the valve responds instantly to the slightest change 
of pressure. 

The clock C and diaphragm steam valves C^ and C" constitute 
the time device of the system. The valve C^ is on the steam supply line 
to the heater, and when actuated by the clock, it opens and blows out 
steam. 

Compressed air is supplied by pipe A'^ and connected with valves 
C^ and C" by A'' operating as follows : Air cock C^ is opened admitting 
air to the pneumatic valve of the clock, the hand is set for the time 
required for the cure. The hand travels to the left, and at the expira- 
tion of the time, it will trip the lever of the pneumatic valve, and thus 
turn on air into pipe A^ which will operate the diaphragms of valves 
C^ and C", thereby shutting off and blowing out the steam, so that 
without the necessity of handling any valves, the heater may be opened 
and the goods taken out. The operation of the clock is independent 
of that of the governor. 

Besides showing the application of the pressure governor and 
time device, the diagram illustrates the Tagliabue plan of piping for 



352 



RUBBER MACHIXERY 




u 



tn 



RECORDING AND CONTROLLING DEVICES 353 

a hose vulcanizer, with the necessary fittings and their location, D 
represents the steam supply from boiler, and D^ D^ D^ D^ the 2-inch 
steam supply to the vulcanizer with three 1-inch inlets. This supply is 
so piped as to give aii equal volume of steam to each of three inlets. 
D" represents 1-inch steam supply to the bottom with two inlets, and 
E E discharge pipe. F F represents the air blow-off valves, which 
are 1% inches to vent the air quickly. 

G G are the mercury thermometers, screwed into special fittings. 
H is R similar fitting for a recording thermometer. This is provided 
with a steam circulation cock, also with an opening for attaching a 
steam gage and pressure governor connection. / is the ordinary spring 
pressure gage. / / represents the recording thermometer with its 
connecting tube, which can be 25 or more feet in length. K is the 
vulcanizer and L the steam separator. 

The Tycos System of Tempeeatuee Control. 
Fig. 367 illustrates the H and M system of automatic heat regula- 
tion applied to a vulcanizer. It shows the application of the type ''S" 
regulator, '"Tycos" recording thermometer '^ Tycos" time valve for tim- 
ing the length of cure and the H and M right side angle thermometer. 

The Tycos Time Valve. 
This device is attached to the press or vulcanizer and allows the 
cure to run exactly the right length of time. Then it automatically 
shuts off the steam and opens the blow-off. The valve is operated by 
compressed air and can be made to operate 20 minutes, 2 hours, 4 hours 
or 21: hours. 

The Ellixwood-Seibeelixg Vulcai^izee. Coxteoe. 

The machine shown in Fig. 368 is designed for accurately timing 
the curing process and for automatically shutting off the steam and 
opening the molds at a predetermined time by a clock mechanism. 
Keferring to the two drawings, A represents the apparatus with the 
molds open and B shows the regulating device in the position it assumes 
when the molds are closed. 

The shaft C, bearing a grooved pulley D, is turned one revolu- 
tion an hour by a clock mechanism (not shown here). The driving 
shaft E is driven by a belt and turns at a faster speed than the shaft C. 
These two shafts may be extended to operate any number of vulcanizer 
molds simultaneously. The lower half F of the mold rests upon the 
frame of the machine and the upper half F^ is hinged by hollow jour 



354 



RUBBER MACHINERY 



nals G, which also serve to admit steam for vulcanization. The upper 
part F^ is counter-balanced by a weight H. In operation, the two 
shafts C and E, being set in motion by the clock mechanism and the 
driving belt respectively, and the press molds being open as shown, the 
mn'ulcanized tire is placed in the lower mold and inflated with live 
steam. The operator then disengages the hook on the end of the con- 
necting rod / from the pin on the lever J , and pushes the lever J to 
the right, opening a three-way valve K and admitting steam to the 
molds. The lever / is thrown back until the hook from the rod / again 
drops over the pin on the lever. The operator pulls the starting rod 
L to the left, causing the driving shaft E to rotate. The four-way 
valve' R is opened to admit water above the piston in the hydraulic 
cylinder J?\ As the piston descends the upper part F^ of the mold 
descends by gravity. The lever S draws in the upper end of the clamp 
arm T down over the top of the mold. As the piston continues to 




Fig. 368. — The Ellinwood-Seiberling Vulcaxizer Control. 



descend, the toggle-joint action forces the molds together. As the 
molds are clamped together the steam valve K opens and live steamj 
is admitted to the molds. When the revolution of the wheel bearing 
the wing-cam X has reached this position its motion is arrested for a] 
definite time to allow the process of vulcanization to be completed. 

Attached to the face of the grooved pulley D is a Avedge block D^\ 
which raises the rod ^Y and engages the ratchet wheel il/\ The fac( 
of the pulley is graduated and the wedge block may be adjusted to raise] 
the rod TT^ after any desired number of minutes up to one hour. Th( 
levers remain in the position shown at B during vulcanization. 



RECORDING AND CONTROLLING DEVICES 355 

When the cure is complete the weighted lever F desceucls and 
forces the rod I and the lever / to the left, thus closing the steam inlet 
and allowing the escape of steam through the exhaust pipe Z. Water 
under pressure is admitted to the cylinder R^ and forces the piston up. 
This also disengages the clamp arm T from the molds. The cross-head 
on the upper end of the piston rod forces the lever Y down and opens 
the molds by assistance of the counterweight H. 

The time during which the molds are closed for vulcanization can 
be arranged for any kind of rubber goods, and the time-shaft auto- 
matically controls the time of vulcanization without attention on the 
part of the operator after the molds are closed. 



CHAPTER XX. 

ECBBEK LABOEATORY EQUIPMENT. 

THE laboratory is today a most important adjunct to the well 
equipped rubber factory. All crude rubber compounding ingredi- 
ents and fabrics, as well as lubricating oils, fuels and general 
supplies, are tliese tested. In its various departments, routine, physi- 
cal, mechanical, electrical and experimental, it is the brain of the 
factory. 

There is probably no industry in which scientific control by chem- 
ical and physical tests and analyses is of equal importance. The raw 
material — India rubber — is produced from various plants, gathered 
and coagulated in many different ways. It contains, besides rubber, 
resins, insoluble matter, nitrogen, ash, water and added impurities 
or preservative substances. 

Crude rubber is usually bought and sold without previous deter- 
mination by chemical analyses of the percentages of the various sub- 
stances present which affect the value of the raw product. It is 
probable, however, that it will eventually be sold on a known 
analysis as are coal, silk, iron ore, sugar, copper and nearly all other 
raw products. 

India rubber, although consisting essentially of the hydrocarbon 
of the formula Cio Hie, has three different constituents, the soluble] 
hydrocarbon, the insoluble part or ""nerve," due to a nitrogenous body,! 
and the resin. 

By chemical tests, therefore, the varying amounts of rubber, the 
resins and the insoluble ^'nerve" containing the nitrogen, can be deter- 
mined. The shrinkage also, consisting of the water and dirt, can be] 
•determined by washing. It is impossible to estimate by inspection 
the amount of water, dirt, etc., in rubber, to within 3 per cent., 
while it can be determined by analysis to less than one per cent. Two; 
per cent, saved on all crude rubber bought would materially add to 
the profits of the works. 

Analysis and general physical examination of vulcanized rubber i 
is of the greatest value. To determine the character and quality of 
rubber contents by a complete chemical analysis and physical examina- 



RUBBER LABORATORY EQUIPMENT 



357 



tion is a difficult and tedious process, vet the total rubber, the earthy 
and oily fillers, the free and combined sulphur, the fabric and the 
resins can be shown in most cases by a few physical tests and the 
determination of the principal chemical constituents. 

Testixg CErDE Rubber. 

In testing, it is necessary to get a small sample representative of 
the mass. Xothing is more heterogeneous than crude wild rubber, 
and getting an accurate sample is therefore difficult and requires care. 

The chemist begins with the rubber as it arrives at the factor}^ 
in biscuits, balls, slabs, crepe, etc. In taking a sample many repre- 
sentative pieces must be cut through and slices taken to get proportional 
inner and outer parts, which will vary greatly in moisture content and 
perhaps in other constituents. Really, from 10 to 20 pounds should 
be taken for the washing test. The sample should be preserved in 
an air-tight container so that no moisture can evaporate. 




Fig. 369. — Miniature Washer, Mixer, Calender, Press and Vulcanizer. 

The whole sample, or a large part of it, should be weighed before 
washing, and preferably the metric weights used. After weighing 
it is sometimes advisable to soften the rubber by heating in water^ but 
this should not be boiling hot. 

Factory washing is described in Chapter I and will serve as a 
guide except that a miniature washer is used. A tank is also advisable, 
so that the dirt can be examined. 

Laboratoey Rubber Machixery. 
Experimental work is done on the miniature machines illustrated 
in Fig. 369. 



358 



RUBBER MACHINERY 



These are a washer, mixer and calender, driven by an electric 
motor, together with a vnlcanizing press and a vertical vnlcanizer. 

The washing consists in repeatedly passing the rnbber between 
the corrugated rolls of the washer. A constant shower of water is 
directed on the rnbber, Avashing out the impurities. Xot only is the 
dirt removed but also soluble substances, such as organic acids, the 
product of fermentation, or substances added to effect coagulation. 




Fig. 370.— Hand Rolls for Washing. 



Ha:n^d Eolls poe Washing. 
For the commercial chemist who has only a few determinations 
to make and is not equipped with rubber washers, it is possible to wash 



on the hand rolls shown in Fig. 370. 



Cylindeical Vacuum Deyee. 

After washing the rubber is dried in warm air or in a vacuum 
dryer. Drying is treated comprehensively in Chapter II and may be 
referred to for guidance in drying test samples. 

The vacuum dryer, shown in Fig. 371, is a cylinder supported on 
an angle frame encased in Russia iron and heated by gas or steam. 

The shell is made of seamless drawn heavy brass tubing, jack- 
eted, with 1-inch steam space. The swing door has a ground joint 



RUBBER LABORATORY EQUIPMENT 



159" 



flanged face and a rubber gasket, and is fastened by wing nnts, ensur- 
ing a perfect air-tight joint. The oven, 16 inches long and 8 inches 
in diameter, is tinned inside and provided with two perforated trays. 
Above and below these trays, at the back of the oven, are two y^r^noh 
perforated brass pipes, plugged on their inner ends, which may be 
used to moisten the material within the oven. The oven is equipped 
with two perforated pipe burners which may be used for gas heating, 
also an adjustable constant level arrangement for the water in the 
jacket. For steam heating a suitable nipple connection is provided, 




Fig. 371. — Cylindrical Vacuum Dryer. 

and in the bottom a drip-cock draw-off for the condensed steam, also 
a stop cock to close connection with the constant level arrangement. 
There are also provided openings for exhausting air and moisture 
from the chamber, for thermometer, vacuum o'a2:e, etc. 



The Feeas Vacuum Ovex. 
The advantages of constant temperature apparatus for chemical 
research and industrial processes are being recognized more and more, 
especially since the advent of the Freas method of electric temperature 
control, insulation, etc. (allowing for continuous unattended opera- 
tion) as employed in the oven illustrated in Fig. 372. 



360 



RUBBER MACHIXERY 



This apparatus consists of a rectangular constant temperature 
electric oven, with cast bronze vacuum chamber properly supported 
inside the oven, fitted with connections for vacuum and passing in 
a stream of hydrogen or other reducing gases. The body of the cham- 
ber is square, with rounded corners. The front, on which the door 
fits, is cast circular and is heavily reinforced, as is the door, to give 
a substantial bearing surface which produces a perfect vacuum-tight 
connection. The door can be rotated in a swivel holder which swings 
on the hinges. This permits of these bearing surfaces being easily 
and accurately gTound in case of need. The central part of the door 




Fig. 372. — The Freas Vacuum Ovex. 

and the back of the chamber are covered with metal screens, on which 
rest mica plates made vacuum-tight with the frame. This permits 
inspection of the chamber by means of the electric lamp at the back 
of the oven beyond the vacuum chamber. The vacuum chamber is 
provided with cast ribs on the sides to accommodate up to 10 shelves. 
Inside dimensions of the vacuum chamber. SxSxlS inches. Tempera- 
ture range, up to 1S0° C, or higher is desired. 

Vacuum Deyer with Coxdexsee. 
The apparatus shown in Tig. 373 has a drying cylinder A 15 
inches high and IS inches long, with about 2 square feet of pan surface. 



RUBBER LABORATORY EQUIPMENT 



361 



The cylinder has a steam inlet B, ontlet C, vapor pipe D, vacuum 
regulator E, thermometer F, vacuum gage G and vent pipe //. The 
vapor pipe passes through a surface condenser I, which has a water 
inlet K and an overflow L. The condensation is collected in the tank 



A -£: 



OM-lirf 



F 




Fig 2)7^. — Vacuum Dryer with Condenser. 

J/. The vacuum is created by a pump T connected with the apparatus 
through a suction pipe 0. The pump may be power driven or operated 
bv the hand wheel P. 



Vacuum Shelf Deyee. 
Referring to Fig. 374, the column A covers the condenser, while 
base B contains a compartment for the condensed vapors. The vacuum 
chamber D is jacketed for steam, hot water or gas. The drying com- 
partment E is large enough to take a pan or tray 18 inches square. 
The door F is locked by levers G engaging lugs H on the ends of the 
door. The progress of the drying is observed through glass windows 
K in the door. The apparatus is frequently employed to determine 



362 



RUBBER MACHIXERY 



the size of drver to use for a given piece of work, the depth and amount 
to load the pans per square foot. etc. The results obtained v\4th this 
apparatus per square foot of pan surface can be duplicated in anv 




Fig. 374. — \'acuum Shelf Dryer. 

larger shelf dryer oj^erating upon the same principle and under the 
same conditions. 



The Sarc+ext Electric Ovex. 
The oven illustrated in Tig. 375 is heated and automatically con- 
trolled by electricity. It may be set for any temperature between 60° 
C. and 150° C. The oven consists of an asbestos lined box bound 
with metal, 12x10x10 inches in size. The two upper shelves are for 
constant temperature work and the bottom one for inorganic work 
at high temperatures. The heating units are in the lovv-er part of the 
box, which has a mica-covered window for observing the glowing wires. 
The temperature is raised or lowered by the insulated milled head at 



RUBBER LABORATORY EQUIPMENT 



363 



the left of the window. A similar head on the left of the oven operates 
a device which maintains the heat controlling device in the position 
in which it is set. The openings at the top are for a thermometer 
and ventilation. The oven operates on either direct or alternating 
current and a 6-foot cord socket ping and a thermometer are fnrnished 
with the oven. 




Fig. 375. — The Sargent Electric Oven. 

The Cexteifugal Sepaeator. 

In separating the insolnble constitnent of the rnbber and in elim- 
inating impnrities snch as small particles of bark, sand, etc., a cen- 
trifngal separator is nsed. 

A solution of the desired strength is made np with a solvent for 
the rnbber and placed in a test tube fitted into containers. After spin- 
ning, all insoluble matter will have settled to the bottom of the tu.be. 
Larger quantities may also be treated in the larger holders. 



IXTEEXATIOXAE ElECTRIC CeXTEIFUGE. 

The well known electric centrifuge, illustrated in Fig. 376, is in 
use in many rubber laboratories. As indicated in the cut, containers 
of several sizes and shapes may be used. The 8-place combination 
head or carrier shown has places for 2 flat-bottom trunnion cups, in 
which can be placed bottles of 250cc. capacity, and places for 6 other 
tubes of varying lengths and diameters from 15cc. to lOOcc. capacity 
each. Squibbs separatory funnels of 150cc. capacity may be used in 
the tw^o larger places. 

This machine stands about 28 inches high and is about 24 inches 
in diameter. The electric motor is built into the base and is specially 



364 



RUBBER MACHIXERY 



designed both mechanically and electrically for efficient service. A 
brake is provided to save time in routine work, and a device connected 
with the brake allows the machine to slow down very gradually at 
the end so as to avoid stirring up fine and light precipitates. A rheo- 
stat is furnished by which the speed may be controlled within wide- 
limits. 

With many of the rubber compounds the density of the precipitate 
is little different from that of the liquid. A high centrifugal force 




I 



Fig. 376. — Internatioxal Electric Centrifuge. 

is therefore required for efficient precipitation, and this is provided by 
the high speed and large diameter of this centrifuge. 

A very considerable variety of other equipment than that above 
described can be furnished with this centrifuge. 

When the sample is dry it is weighed. The weighing of both 
wet and dry samples is done on an apothecary's scale having metric 
weights. 



RUBBER LABORATORY EQUIPMENT 



365 



The washing and drying not only determines the loss or shrinkage 
but so masses the sample that it is nearly uniform, and laboratory 
samples can be taken from it. Crude rubber cannot be ground or 
shredded easily, so that cutting with scissors is the best way to obtain 
fine pieces. Having determined the factory loss by an imitation of 
factory methods, the chemical analysis proper is begun. The weighing 
of, say 5 grams, must be done on a chemical balance. 

Scales and Balances. 
The success of chemistry has been due, more than all else, to 
the use of accurate wei^'hts and measures and keeping careful, written 




Fig. 377, — Analytical Balance. 



records. Too much detail will distract the attention from the main 
issue, but taking notes during an experiment isv-^a ^ real relief to the 
mind, and pays in the long run. 

The question of weights is of the utmost ^-ihaportance. The use 
of liquid measures has been very generally abandoned in favor of 
weighing, as being more accurate. Balances are true, however, only 
within a comparatively small range; but by means of the wonderful 
series of weighing apparatus now on the market, it is possible to weigh 
anything, from a steamship to a pencil mark. 



366 



RUBBER MACHINERY 



There are many types of balances for fine weighing. One, for 
example, is so delicate that it indicates a difference in weight of one 
five-hnndredth of a milligram, or less than one fonrteenth-millionth of 
an ounce. For snch balances there is furnished a unit-weight, weighing 
29.1666 grams; so that in quantitative analysis, on the basis of this 
unit, each milligram represents one troy ounce per avoirdupois short 
ton. The bearings in these balances are agate planes^ resting upon 
agate knife edges. 

The analytical balance, illustrated in Fig. 377, has a capacity up 
to 100 grammes in each pan, and is sensitive to one-twentieth of a 
milligram. It is provided with a short beam, graduated on both sides 
of the centre agate for a 6-milligram rider, the beam blackened and 
graduations filled in white, which greatly facilitates the readings. It 
has agate knife edges and bearings with improved hangers and triple 
arrest, raising the hangers from knife edges as well as the beam. The 
wide pans and bows accommodate a dish 10 cm. in diameter. There 
is an improved arrest for pans with automatic stop and red graduations 
on the index enabling close readings. It has a finely polished mahog- 
any and glass case with leveling screws and counter-poised sliding 
door, mounted on heavy black glass sub-base. 




Fig. 378. — Counting Scale. 



Fig. 378 shows the multiplying scale, for use in counting small 
articles of the same kind. This has a capacity of four pounds, and is 
sensitive to one two-hundredth of an ounce. They are usually made 



RUBBER LABORATORY EQUIPMEST 



367 



to count by tens or dozens, tliongh larger multiples could be supplied 
to order. In using, a dozen of the articles, laid on the long arm, 
will just balance a gross of the articles on the short beam. 

Rubber chemists have always been accustomed to test the specific 
gravity of rubber samples. For this purpose there are special hydro- 
static scales, for weighing in water. There- is a -stimple halance of 
this type, and also a combination balance, w^hich can be used for ordi- 
nary weighing as well as weighing in water. This combination is an 
all around useful balance, having a capacity of one kilo, and sensitive 
to one-half centigram. Some of the finer balances, sensitive to one- 
twentieth milligram, have also an apparatus for taking specific gravity. 

For weighing cloth, or sheeted material of uniform thickness, there 
are balances provided with a cutter to take out a small unit square, so 
that the indicator gives the weight of a square yard wdthout the neces- 
sitv of calculation. 




Fig. 379. — Manufacturers' Estimator. 



There is a type of balance called an estimator, very convenient 
for rubber compounding. This is illustrated in Tig. 379. AVhen a 
small amount of compound is weighed, the indicator will show, at 
the time, exactly how much of the material will be needed to make a 
batch of rubber for any desired weight or number of similar articles, 
and this with greater accuracy than can usually be done by figuring. 

When balances are occasionally moved, it is best to have them 
fitted with screw feet and a spirit level, so that they can be trued up 
for any table or counter. The hangings are of aluminum, for light- 
ness, and the metal parts should be of platinum, brass, or other- 
Avise made non-corrosive. It is best to have the whole enclosed in 



368 RUBBER MACHIXERY 

a glass case, to exclude dust, aud to keep the metal parts at an even 
temperature. Verv line readings must be done with a magnifying 
glass. 

Usually a set of weights goes with each balance, but these can 
always be found in the general market, too, ranging from a milligram 
(about one twenty-eight-thousandth of an ounce) to 50 pounds. The 
metal of these must be non-corrosiye, since corrosion increases their 
weight and destroys their accuracy. 

ExTEACTIOX ApPAEATUS. 

Different organic compounds are soluble in different volatile solv- 
ents, and this is taken advantage of in many processes. AVhere the 
sample is subjected to washing by a volatile solvent which is con- 
tinually re-distilled from the dissolved portion and applied again to 
the substance examined, the process is called Soxhlet extraction. This 
is probably the most important process used in rubber analysis. The 
resins are soluble in alcohol, acetone, methyl and ethyl acetates, which 
are water soluble solvents. Crude rubber is soluble in benzol, gasoline, 
chloroform, and many other water insoluble solvents. The inorganic 
dirt is insoluble in all these. Thoroughly vulcanized rubber is insolu- 
ble in everything which does not decompose it. 

Vulcanized rubber is, however, soluble in volatile solvents which 
will not dissolve or destroy the inorganic fillers or the fabric. Some 
of these solvents dissolve the vulcanized rubber and the combined 
sulphur. The free sulphur is easily removed with acetone. 

Moreover, the pectous rubber or the "nerve" can be separated by 
extracting out the soluble hydrocarbon with a' petroleum fraction at 
reduced temperatures. It will thus be seen that this extraction with 
volatile solvents is useful for many separations in the rubber analysis. 
In reclaimed rubbers which have been properly vulcanized, as much as 
25 per cent, of the rubber can be extracted with chloroform after the 
acetone extraction. 

Soxhlet ExtPvACtiox. 

Soxhlet extraction with both hot and cold solvents is therefore 
the main reliance in rubber analysis. The original Soxhlet appara- 
tus, illustrated in Fig. 380, consists of a set of 6 extractors and water 
bath, heated by gas or hot water. The flask at the bottom holds the 
volatile solvent, which is continually distilled by the heat. Above 
this is the extractor tul}e, with a side tube leading the vapors to the 
top, and a small siphon tube for emptying the extractor when it becomes 
flooded. Above the extractor tube is the condenser, consisting of a 



RUBBER LABORATORY EQUIFMEXT 



369 



bulbed tnbe inside a larger one thiongii which water flows. The 
sample is supported on a wad of cotton or in a paper tube with cloth 
tied over the bottom and placed in the extractor tube below the con- 
denser so that the condensed solvent will fall on it. The volatile 
liquid in the flask vaporizes and passes into the extractor tube at the 
bottom, thence through the side tube to the top of extractor tube, 
thence up into the condenser, where it is condensed and falls down on 
the sample in the extractor tube. The soluble parts are dissolved and 
carried to the flask at the bottom, where the solvent is a^'ain distilled 




II fl HI] 11 tl 





Fig. 380. — Soxhlet Extractors. 



ofl^, leaving the extracted substance in the flask. When the solvent 
remains clear the extraction is complete. With proper regulation of 
the heat the operation is constant and automatic. 

The sample is then removed from the extractor, dried and weighed. 
The loss represents the soluble part. If the flask is disconnected and 
kept on the bath until drv, and then weighed, the increase of weight 
is the substance dissolved and should check with the other weighing. 
Of course the sample and flask are both weighed before analysis. 



370 



BUBBER MAC RISE BY 



For rubber work this apparatus is objectionable, for several rea- 
sons. First, rubber stoppers are, of course, inadmissible, so that 
cork must be used, and this is seldom tight and frequently contains 
substances removed by the solvents. Secondly, the substance is kept 
comparatively cold vrhile being extracted, while hot solvents are neces- 




« 




Fig. 381. 
Extractor with Ground Joints. 




Fig. 2>%2. 
Extractor with ^Mercury Seal. 



sary in many rubber analyses. To avoid stoppers, ground joints are 
sometimes used, as shown in Fig. 381, and mercury seals are employed, 
as shown in Fig. 382. The latter is the Knorr Hask, which has a depres- 
sion around the neck to receive mercury. 

Dr. Wiley developed the extractor shown in Fig. 383. This 
was modified by Ford as shown in Fig. 3Si.^ Here, the idea is to have 
the large test tube in which hangs the condenser and extractor tube. 
The TTiley condenser is made of metal while the Ford modification 
is of oiass. 



= See "Journal of the American Chemical Society," April, 1912. 



RUBBER LABORATORY EQUIPMENT 



371 






Fig. 383. 
Wiley Extractor. 



Fig. 384. 
Ford Extractor. 



Fig. 385. 
Landsiedl Extractor. 



An extractor which has many good points is the Landsiedl, sho^^m. 
in Fig. 385. This has only one gronnd joint. The apparatus is all 
glass and the extraction tnbe extends down into the neck of the flask 
and is kept heated. Several different extraction tubes are furnished — 
A and B, used for solids ; C, used for liquids heavier than the solvent 
(the solvent flowing over), and D for solvents heavier than the liquid 
examined, the solvent percolating down through the liquid and arising 
from the bottom through the siphon. 

The Bailey- Walker Apparatus. 
The extractor shoA\Ti on the right in Fig. 386 is equipped with 
a modified form of metallic condenser having a large condensing sur- 
face, which has proven entirely satisfactory when used with ether, 
even in the warmest climate. It has the following advantages: An 
inexpensive, durable and efficient condenser, which may be adapted 
to practically any form of continuous extraction apparatus ; the elimi- 
nation of all rubber, corks, ground glass or mercury seal connections ; 
extractions may be safely run over night, since there is practically no 
danger of breakage due to change in water pressure; the flask is 
light enough to be accurately weighed ; and it is easily cleaned and of 
such form that all of the extract can be transferred. 



372 



RUBBER MACHINERY 



The illustration on the left shows a conveuient and compact 
manner of connecting the condensers with water supply and waste 
pipe. The small tube entering the inlet tube of the condenser should 
be of copper preferably, and one-eighth of an inch in outside diameter. 
The iron pipe which receives the outlet tube should be three-quarters 
of an inch in diameter and of such height that the bottom of the con- 
denser will not touch the heating plate when the flask is removed. The 



WATER SUPPLY 





Fig 386.— The Bailey-Walker Apparatus. 

apparatus is compact; seven of them can easily be accommodated on 
an electric hot plate 24x41/2 inches. If this type of plate is used 
it should be fitted with three heats, the high heat so arranged that 
it will ignite ether. 

Underwkiters' Extkactiok Apparatus. 
Of late there has come into prominence what is known as the 
''Underwriters' Extractor," a slight modification of which is shown 
in Fig. 387. This is the standard adopted by the analysis section of 



RUBBER LABORATORY EQUIPMENT 



373 



the Joint Rubber Insulating Committee.^ It is easily seen that this 
is a development of the Wiley extractor, in that the condenser is of 
metal projecting into the flask. Only two criticisms need be made of 
this extractor. First, the metal condenser may be acted upon hy 



^Zsmrrr of/fs /We c//ar. 
b/ock tin Tub/nq. 




/fll d/mensions in millimeters. 

Fig. 387. — Underwriters' Extraction Apparatus. 

some solvents, particularly the chlorinated compounds. Second, there 
is apt to be an escape of vapors through the cork or lid. It would 
appear that there would be an advantao^e in havina: the lid of the 



^See "Journal of Industrial and Engineering- Cliemistry," January, 1914. 



374 



RUBBER MACHINERY 



underwriters' extractor made in hollow stopper form. The condenser 
might also be made of twisted glass tubing without great difficulty. 

In the analysis of crude rubbers an extraction of the dried rubber 
with acetone is of importance, to determine the amount of resin. ]N'ext, 
an extraction with a certain petroleum fraction under correct tempera- 
ture conditions gives the amount of pectous rubber or "nerve." 

Electeically Heated Apparatus. 
Sargent's apparatus, shown in Fig. 388, wull accommodate almost 
any style of glass extractors, all necessity for sliding the corks on 




Fig. 388.— The Sargent Electrically Heated Apparatus. 



the tubes in order to remove any part of the glassware being obviated. 
The condensing tube itself slides easily through the cooling tank, en- 
abling any flask or extractor, or both, to be removed from the cork 
and not the cork from the glass parts as in other forms of support. 



RUBBER LABORATORY EQUIPMENT 375 

As there are no valves or washers used, it is impossible for the cooling 
tank to leak where the tubes pass through. The water enters at the 
bottom, passes up through the center column and is carried dowTi to 
the bottom of the condenser, the warmer water rising by gravity and 
overflowing. It passes down again through the center column and 
is voided on the opposite side of the base, making only one inlet and 
outlet necessary and doing away with the mass of rubber-jointed indi- 
vidual condensers, with their clamps, heretofore used. 

The center column is elastic and may be adjusted to suit different 
leng-ths of extractors. The minimum distance obtainable between bot- 
tom of the tank and the hot plate is 15 inches, the maximum 24 inches. 
It is alw^ays best to adjust the height of the tank in such a way that 
when everything is in place only one inch of the condensing tube 
appears above the tank. 

Multiple Uxit Electric Heatee. 
The wide application of electrically heated hot plates has dis- 
closed the necessity for temperatures higher than those heretofore 
attained, but with less expenditure of current and quick replacement 
of heating units for emergency repairs. The Multiple-Unit hot plate 
illustrated in Fig. 389 is of the type in which the units are readily 




Fig. 389. — Multiple Unit Electric Heater. 

renewable by the operator. The base and top are cast iron, and the 
units, 2 or 4 in each plate, are of moulded '^Electrobestos," grooved to 
receive the heating elements, which are imbedded in a refractory cement. 
The top plate rests on the units, free from contact w^ith the base, which 
prevents loss of heat by conduction. The units rest on bricks of 
low thermal conductivity, having a conductivity of about one-tenth 
that of ordinary fire bricks. This forces to the top of the plate a 
maximum amount of heat generated and affords a comparatively cool 
atmosphere to the underside of the apparatus. The increased efficiency 
is a net saving in current cost; gives higher temperatures and quicker 



376 



RUBBER MACHIXERY 



maximum heats. All sizes, whether of the three^ieat or single-heat 
type, give maximmn temperatures of at least 750° F. (400° C.) The 
three-heat type gives approximately 400° F. (250° C.) on low heat 
and 600° F, (315° C.) on medium heat, when used on 110 or 220 volts. 



Digestion Flasks axd Distillix^g Appaeatus. 
Separate determinations of nitrogen are made by the Kjeldahl 
process, in which the substance is boiled with mercury and acid until 
all is decomposed and the nitrogen converted into ammonia. Then 
the ammonia is distilled off into standard acid, and the amount neu- 
tralized shows the amount of nitrogen as ammonia.* It is necessary 
to discriminate between the nitroacn of the rubber and that of the 




Fig. 390.— The Spy Fumeless Digestion Apparatus. 



*See "India Rubber Laboratory Practice," page 9, by W^. A. Caspari, also 
"Proceedings of the Official Agricultural Chemists," published by the Agricul- 
tural Department, Washington, D. C, where the best standard methods are given. 



RUBBER LABORATORY EQUIPMENT 



377 



impurities, as the former is advantageous while the latter seems to 
exert a deleterious effect. The following digestion and distilling appar- 
atns are nsed in this work. 

The Spy Fumeless Digestiox Appaeatus. 
This apparatus, illustrated in Fig. 390, permits of digestions being 
made in any place having a water supply and drain, without the use 
of fume closet. The fumes produced in the flasks will be sucked 
through the bulb tubes or absorbers to the drain as long as water is 
connected with the pump and running at a fairly good pressure. The 
flasks can be taken out of the ring clamps to gently shake contents 
without dismantling the apparatus. The entire apparatus is porta- 
ble, each part being neatly fitted to the heavy iron support. 

The Kjeldahl Distillixg Appaeatus. 
A most convenient form, that can be made to hang on the wall 
or with support to stand on the table, is shown in Fig. 391. It 




Fig. 391. — The Kjeldahl Distillixg Apfaratus. 



comprises a polished heavy copper condenser with block tin condensing 
tubes, support for flasks and a set of E. k A. adjustable burners for 
use with natural illuminatino; or pasoline 2:as. 



378 



RUBBER MACHIXERY 



ViSCOSIMETEES. 

The testing of rubber solutions for viscosity is a physico-chemical 
test but may be made of importance if the uncured or raw rubber is 
dissolved in a standard solvent in a definite way. Fig. 392 shows the 
Saybolt or American standard, and Fig. 393 shows the Engler or 
European standard viscosimeter for petroleum testing. These depend 
on the dripping of a definite quantity of solution through a hole of 
certain size while temperature and other conditions are standardized. 
Fig. 394 shows the Doolittle viscosimeter, which depends on the twist- 
ins: and untwisting' of a wire and its retardation to show the viscositv. 




■{a) OU-Tube 
-(^ Bath Thennometer 
■(C) Electric Heater 
■^D) Turn-Table Cover 
\E) Overflow Cup 

Fj Tum-Table Handles 
iG) Steam Inlet or Outlet 
■(h) Steam U-Tube 
-Q) Oil-Tube 
■QO Stirring Paddles 

I Bath Vessel 
-{Mj Electric-heater Receptacle 
[Nj Outlet Cork-Stopper 
PyGas Burner 
Strainer 
■^)Recei\-ing Flask 
Base Block 
Straining-Cup 



Pipette 
VVTuhe-Cleaning Plunger 



The Saybolt Viscosi:^rETER. 



Eedwood"^ describes all kinds of viscosimeters at great length, and 
all works on petroleum or oil analysis usually describe several. Thus 
Lewkowitschf describes the Engler, Saybolt. Eedwood and other vis- 

*"Petroleum and its Products," bv Sir Boverton Redwood. Second Edition, 
1906: Third Edition, 1913. v, -c^ t 

fChemical Analvsis of Oils. Fats and V^'axes," by Dr. J. Lewkowitsch, t. i. 
C. F. C. S. ; London, 1898: also later editions. 



RUBBER LABORATORY EQUIPMENT 



379 



cosimeters. Testing the viscosity of a rubber solution is about the 
only way known to determine the relative polymerization of the rub- 
ber; and the value of the rubber depends largely on its state of poly- 
merization. 





f 




Fig. 393 
exgler viscosimeter. 



Fig. 394. 

doolittle viscosimeter. 



Fig. 395. 
ostwald viscosimeter. 



The Ostwald Viscosimeter. 
Fig. 395 shows the viscosimeter largely used by rubber chemists, 
particularly in Europe, owing probably to Ostwald's prestige as one 
of the greatest authorities on colloids. It consists of a single U-shaped 
glass tube expanded into bulbs at two points and contracted at one 
point to a capillary tube. In use, the tube is filled through F until 
the lower bulb E is nearly full. Then the apparatus is plunged 
into water of definite temperature, and when it has attained this tem- 
perature the solution is forced up until it passes through the capillary 



380 



RUBBER M AC HI X FRY 



tube B to the bulb K, filling it to above the mark C. This is done by 
air pressure ou F or suction on A. The pressure of suction is then 
removed and the liquid level allowed to fall to D, the time being- 
noted that it requires to pass from C to D. This time is the measure 
of viscosity. The instrument is graduated by determining the time 
that water or some other standard liquid takes to flow through the 
same space, from C to D. One advantage of the apparatus is its sim- 
plicity and ease cf cleaning and of keeping under a fixed temperature. 
It will not, however, work on very viscous solutions and is never used 
in the petroleum industry in the United States, where viscosity detej.'- 
minations are of most importance and made on the largest scale. 



The Feaxk Viscosity Appaeatus. 
Dr. Fritz Frank proposed for the German section of the Inter- 
national Testing Committee an apparatus to consist of the following 
parts (Fig. 396) : The receiver A is a pear-shaped glass vessel, with 
an inflow socket B provided with a ground stopper, and at C with a 
similar socket which carries the aluminum closing rod D. The vessel 
has three marks for the measurement of 200cc. The three marks 



L 




D- 


^F 


^-i 


^ 


wvf''-^ 


'It 


\ 


JL" 


^A 




Fig. 395. 
The Fkaxk Viscosity Apparatus. 



Fig. 397. 
The Jolly Spiral Balaxce. 



RUBBER LABORATORY EQUIPMEXT 381 

serve for measuring in and at the same time for the establishment 
of a certain level, xlt the lower end, the vessel has a discharge pipe 
E of metal of a predetermined leng-th, which is firmly set in a glass 
socket. The closing rod D is gronnd to close this ontlet perfectly and 
is carried by guides in the holder F. By means of the gronnd collar 
G, the glass vessel A is attached to the receiving cylinder H. Both 
grindings have connecting openings at / to allow the air to escape, or 
by slightly tnrning the vessel A they may be closed. The receiving 
cylinder H is graduated, and from the 95 cc. to the 105 cc. mark 
is contracted to permit accurate reading. The cylinder is mounted on 
a broad wooden base K. The dimensions are invariable. 

In use, the discharge opening is closed and the glass retort A is 
filled with the solution exactly to the 200 cc. mark. For the measur- 
ing temperature, 20° C. is always employed. In the older apparatus, 
the cock was turned from stop to stop ; in the new apparatus, the clos- 
ing rod D is raised by a quick but steady movement to the stop and 
at the same time the stop-pin of the stop-watch (seconds watch) is 
pressed open. As soon as the fluid has run as far as the 100 cc. 
mark down into the lower vessel, the closing rod and stop watch are 
simultaneously set and the elapsed seconds noted. As so far no unit has 
been established, it is possible only to give the time required for 100 
cc. of the solution to run out. The second determination of viscosity 
is carried out after 8 or 10 days with the remainder of the solution, 
whidi must be kept in a dark place. 

Apparatus for Detekminuntg Specific Gravity. 

The ratio of bulk to weight is of great practical importance in 
the rubber industry, because it controls the number of pieces or feet 
per pound obtainable from any given stock. This relation of bulk to 
weight is dependent on the specific gravity of the material. Its deter- 
mination presents a constantly recurring problem. 

The method of determining specific gravities of solids depends 
on the fact that any substance immersed in water loses weight equal 
to the weight of the volume of water which it displaces. The means 
of ascertaining specific gravities vary somewhat according as the sub- 
stance under examination is solid, liquid, or a gas. The density of 
any substance bears the same proportion to the density of w^ater as the 
weight of the substance bears to the weight of its bulk of water. Hence 
if the weight of the body, in air, is divided by its loss of weight, 
w^hen weighed in water, this quotient will represent the specific gravity 
of the bodv. 



382 RUBBER MACHIXEBY 

Every chemical balance is provided with a hook at either end 
of the beam for nse in suspending a sample to permit its weight to 
be taken in water, the glass containing the water being placed on a 
support standing on the floor of the balance case and astride the scale 
pan. 

The Jolly Spiral Balaxce. 

The Jolly spiral balance, so called from its inventor, is especially 
useful for obtaining raj)idly the specific gravities of minerals and 
rubber samples. It is illustrated in Fig. 397 and consists of an up- 
right supported on a heavy iron base, which is provided with leveling 
screws. Extending the full length of one side of this upright is a 
mirror upon which is engraved a fine decimal scale. Sliding on the 
upright is a small adjustable platform for supporting a glass of 
water. Within the upright is a light adjustable wooden rod carrying 
an arm for holding one end of the weighing spiral of wire which 
supports at its lower end the connected pans. Three spirals of various 
degrees of tension are provided with the instrument to regulate its 
sensibility to heavy, medium, or light materials. The pans are sus- 
pended from the medium spiral, the lower pan of glass, hanging freely 
in a receptacle filled with clean distilled water. If such water is not 
available, clean cool water, that has been previously boiled to expel 
the dissolved air. will answer very well. 

To make a specific gravity determination, begin by adjusting 
the glass of water at such a height that the lower pan will be immersed 
to some point above where its supporting wires meet. Allow the pans 
to come to rest, and note the reading on the scale of the height of 
some fixed point, as the top of the white bead. The scale is engraved 
on a mirror in order that a level reading may be taken by sighting 
the point selected for reading with its reflection. Every reading must 
be made from one reference point. Record this reading taken with 
the pans empty. Then place in the upper pan a small piece of the 
rubber or other material to be tested, of suitable size (and any shape). 
Again adjust the level of the glass so that the pans may hang free 
and with the lower pan immersed as before. When equilibrium is 
established note the second reading of the same reference point and 
record. In precisely similar way determine the reading of the refer- 
ence point again with the sample in the lower pan immersed. Care 
must be taken to free the sample of all adhering air bubbles which 
would otherwise falsify the reading. Xote the third reading and the 
data will be ready for calculation. These readings represent, in terms 
of spaces on the scale, (1) the weight of the pans unloaded; (2) the 



RUBBER LABORATORY EQUIPMENT 



383 



weight of tlie pans and substance in air; (3) the weight of the pans 
and substance in water. 

The difference between the first and second readings stands for 
the weight of the sample in air. The difference between the second 
and third readings represents the loss of weight -of th« sample in 
water. Divide the weight in air by the loss of weight in water and 
the result will express the specific gravity. For solids lighter than 
water it w^ill be found necessary to close the wires of the lower pan 
more or less around the sample to keep it immersed. 



The ^N^icholson Hydrometer. 
Another and simpler instrument for obtaining specific gravities 
of solids is shoA^Ti in Fig. 398. This is made of thin sheet metal of 






Fig. 399. 



The Nicholson Hydrometer. 



-Ordinary Hydrometer 
AND Cylinder. 



hydrometer form, and provided with a set of small weights. It is inex- 
pensive and accurate, but not as convenient to use as the Jolly balance. 
Above and below the body of the hydrometer are pans for holding the 
sample. On the stem is a reference mark to which point the instru- 



38i RUBBER MACHIXERY 

iiient is always sunk in the jar of water before each reading is taken. 
Briefly described, its use is as follows : ^ Let Wx be the weight required 
to sink the instrument to the mark on the stem, the weight of the 
instrument being w ; to take the specific gravity of any solid substance 
place a portion of it weighing less than ii\, in the upper pan, with 
such additional weight, say Ws, as will cause the instrument to sink 
to the zero mark. The weight of the substance, in air, is then ii\ — zr^. 
Xext transfer the substance to the lower pan, and again adjust with 
weight Wi to the zero mark. The loss of weight of the substance in 
water is then w^ — w-^. Therefore the specific gravity is obtained by 
this formula : 

ti\ — Ws 
Specific gravit}'= 

Tor materials in the form of powder the specific gravity bottle 
is used. This is of various forms, but is essentially a small flask pro- 
vided, with a reference mark on the neck. A fine chemical balance 
is necessary to make the weights and the procedure is as follows for 
solids heavier than water : " Weigh the flask filled to the mark witL 
w^ater. then place the substance, of known weight, in the flask, fill to 
the mark with water, and weigh again. The calculation will be : 
(AYeight of substance in air) + (weight 
of fiask and water) — (weight of flask 
and water and substance) 

s. a= 

(weight of substance in air.) 

Specific gravity is not to be taken as a test for quality as applied 
to rubber stocks, but simply as a guide to the economy of the stock. 
Another practical application is found in estimating the weight of a 
proposed article of solid stock when its cubical contents is kno^^m. 
The weight for water of the cubical contents is ascertained by multi- 
plying by 252.5, the weight in grains of one cubic inch of water. 
This product multiplied by the specific gravity of any material will 
give the weight of the object in that material. Thus an article of 10 
cubic inches volume would weigh, if made of a rubber stock of 1.85 
specific gravity: 

10X252.5X1.85=4671.25 grains=10 2/3 oz. 

Turning to the consideration of the means of obtaining the gravi- 
ties of liquids such as acids, oils, naphtha, etc., we have the various 



'From Bailey's "Chemists' Pocket Book." 



RUBBER LABORATORY EQUIPMENT 



385 



forms of hydrometers and balances. There are many specially designed 
hydrometers adapted to the requirements of certain industries, but m 
principle they are all alike. 

Ordiis^aey Hydeometer axd Cylits^dee. 
Fig. 399 shows the ordinary type of hydrometer, which consists 
of a weighted glass bulb sinking the instrument upright in the liquid. 
The degree or actual specific gravity is read by means of graduations 
on the stem. The ordinary Beaume hydrometers are those in general 
use. Two instruments are required, one weighted and graduated for 
liquids heavier than water and one for those lighter than water. The 
Beaume scale of "degrees" is arbitrary and to ascertain the specific 
gravities a table must be consulted. Tor ordinary trade purposes the 
Beaume degree is used and is all that is required. 

The Westphal Balance. 
The balance shown in Fig. 400 is adapted to either light of heavy 
liquids and by its aid the gravities are read direct from the weights 




Fig. 400. — The ^^'ESTPHAL Balance. 



used without calculation. It is also convenient when only small sam- 
ples of liquids are available for examination. The balance is so 
readily adjustable that the glass bob will balance the counterweight 
on the opposite arm when hanging in air. When suspended in any 
liquid a buoying effect, dependent on the gravity of the material, 



386 



RUBBER MACHINERY 



throws the instrument out of balance. The equilibrium is re-established 
by a set of rider weights. Reading the position on the beam of the 
weights in the order of their size gives the specific gravity at once. 

The Young Gravitometer. 

A direct reading specific gravity balance for solid, pigments or 
other finely divided materials insoluble in water is shown in Fig. 401. 

The balance is leveled by a screw in the base, as seen in the 
figure on the left. The sample of rubber or other material to be 
tested is suspended on the needle point and the weight on the beam 
moved in the direction necessary to bring the index to the point 




Fig. 401. — The Young Gravitometer. 

marked oo on the graduated arc. The glass vessel, filled with water, 
is then placed on the platform, which is raised until the sample is 
fully immersed. The pointer will then move along the scale and indi- 
cate the specific gravity, as shown in the figure on the right. 

For testing pigments, a receptacle is provided, which is suspended 
in the place of the hook. The operation is the same as with solids, 
except for the use of the counterweights. 



The Rost Apparatus. 
Fig. 402 shows an apparatus which consists of a graduated cylin- 
der A fixed in a wooden base, two pipettes B and C for filling and a 



RUBBER LABORATORY EQUIPMENT 



387 



solution of chloride of zinc with a specific gravity of 200. The pro- 
cedure is very simple and quickly gives the exact statement of the 
specific gravity. 

For the denser grades of rubber which are likely to be heavier 
than 0.45, fill the cylinder with zinc chloride solution exactly to the 
lowest line, 2.0 — if possible without wetting the upper jDart of the 
tube. This is done with one of the pipettes. Then put the piece of 
rubber in the cylinder, having first moistened it, to prevent air bubbles. 
If the rubber is specifically lighter than 2.0 it will be suspended in 
the upper part of the mixture. ]^ow add water with the other pipette, 
drop by drop, frequently stirring the fluids, as long as the piece of rub- 




FiG. 402.^The Rost Apparatus. 

ber is in the midst of the mixture. The mixing is best done by slowly 
turning the cylinder after having closed it with a stopper. Heavy 
shocks are to be avoided. The number on the left of the cylinder 
which the liquid has reached, after standing a short time, gives the 
specific weight of the rubber. 

For rubber having a weight of 1.0 and 1.5, a contrary procedure 
is adopted. Fill the graduated cylinder with water to the line 1.0 
on the right side, then add zinc chloride solution as described above, 
until the piece of rubber is swimming in the mixture. The number on 
the right side of the scale gives the specific weight of the rubber. 



Specific Gravity axd Compound Cost Calculatoe. 

Young's device, illustrated in Fig. 403. is used for calculating 

gravities from the formulae of compounds. It will be seen that the 

important compounding ingredients have been plotted on the slidablo 

chart, on lines which correspond to the reciprocals of their gravities. 



■388 



BUBBER MACHIXEBY 



The operation for determining the specific gravity of a componnd. 
from its formula is as follows : The slide B is moved vertically imtil 
the index .4. is at the percentage of the first ingTedient. Then the 
cross slide is moved until the index C is at that ingredient's line, and 
the runner is moved to the left on the cross slide until it comes to 



-J 




M" 



I 



Pig. 403.— Specific Gravity and Compouxd Cost Calculator. 



the left stop. The slide B is then moved so that the index A registers 
at the percentage of the next ingredient, and the cross slide carrying 
the rnnner is moved to the right until the runner index is on that 
insredient's line. This operation is repeated imtil all of the ingredi- 
ents have been introduced, and the gravity is read on the upper scale 
imder the hair line. 

Tor an ingTedient which has no line on the chart it is possilde 
to interpolate between the lines as plotted, knowing, of course, the 
gravity of the ingredient. 



RUBBER LABORATORY EQUIPMENT 



389- 



The slide B is reversible, and on the opposite side are lines 
which may be used in the calculation of compounding cost, or the- 
batch weights from the percentages in the compound. 

Sampliistg. 
E'early all vulcanized rubber can be ground on the rubber mill, 
shown in Fig. 369, to any required degree of fineness, and where 
these machines are available they are the most satisfactory means of 




P2.*^ 



Fig. 404. — Grinding Mill. 



getting a sample of most goods. The Joint Rubber Insulating Com- 
mittee"^ prescribes the mill shown in Fig. 404. In this the grinding 
plates are adjusted so that not more than 20 per cent, of the rubber 
will pass through a 40-mesh sieve. The material is then sifted through 
a 20-mesh sieve and is ready for use. For the analysis of the inor- 
ganic fillers the usual laboratory apparatus is used. 

Physical Testing of Rubber. 
The value of rubber goods usually depends on the peculiar elasticity 
and resilience of rubber itself, together with its electrical resistance in 
some cases. Its resistance to water and the elements generally is also 
important, as is its resistance to chemicals. Therefore the physical 
testing of manufactured rubber articles is of greatest importance. 



"'Journal of Industrial and Engineering- Chemistry," January, 1914. 



390 RUBBER MACHIXERY 

The tensile strength of most rubber goods can be determined on 
an}^ of the usual tension machines, provided they are adapted to take 
care of the great stretch. 

Test Pieces. 

The European testing machines as a rule call for rings, while the 
American specify strips. Mills, who has done research work for the 
largest American rubber plants, thus discusses the tAvo forms and 
describes his strip cutting apparatus. 

■^''Although the ring form of test piece is popular, many prefer 
the straight test piece, as it does not involve certain errors to which 
the ring is subject. 

^Tig. 405 shows a hand operated press for cutting standard 
test rings, and Fig. 406 shows a device for cutting test strips. 




Fig. 405. — Punch Press for Standard Rings. 

''All those who have tried punching test pieces will appreciate 
the difficulty in preparing imiform pieces of a regular cross section 
that can be easily measured. The softer the stock the more it yields 
under the knife or punch, and the more likely vrill the section depart 
from the desired shape. 

Strips may be molded into the desired form, but it is difficult to 
obtain uniformity throughout the narrow portion. It is essential that 
the section should be uniform and easily measured, also that the 
edges should be clean, as a tear will readily follow a slight check. 
It has been found much more satisfactory to punch away the sides 
of a flat strip, leaving the test portion between two stout ends. 



*H. P. MiUs, "Journal of Industrial and Engineering Chemistry," June, 1912. 



RUBBER LABORATORY EQUIPMENT 391 




Fig. 406. — Device for Cutting Test Strips. 




Fig. 407.— Punch Press for Straight Strips. 



392 



RUBBER MACHINERY 



'The strip is molded in bolted molds. Eeferring to Fig. 407, a 
sharp, thin, cnrved knife is set firmly in the vertical slide. A stop 
prevents it from touching the cast iron bed plate. A 'nest' into which 
the strip fits snugly prevents the rubber from spreading while being 
cut. The nest is secured to the bed plate by thumb screws, and it 
can be adjusted to the thickness of the strip. 




Fig. 408. — Straight Strip Cutter. 



"A few thicknesses of manilla paper are placed under the strip 
in the 'nest' and one side is punched out. The knife is so shaped that 
a little of the rubber at each end is left uncut; thus, when the strip 
is lifted out, the punched pieces still adhere to it. Without removing 
this piece the strip is replaced in the nest, this time with the cut 
edge forward. Care is taken to have the same surface up in both cases, 
as the parallelism of the width of the test pieces is thereby assured. 
The second side is punched out, the strip taken out of the nest and 
the punched pieces torn or cut free. Two marks at a unit distance 
are then placed on the strip, which after measuring is ready for 
testing." 



RUBBER LABORATORY EQUIPMENT 



393 



Gkia^der for Test Pieces. 
The maclime shown in Fig. 409 is for the purpose of preparing 
samples of uniform cross section to be used for tests for tensile strength. 
It was designed primarily for grinding off the rubber in preparing 
samples for testing the breaking strength of rubber hose lining. 




Fig. 409. — Grinder for Test Pieces. 



The rubber-backed interior lining is stripped from the fabric of a 
section of hose several inches in length. This strip of rubber is cut 
to a uniform width of one inch throughout a distance of 3 or 4 inches 
along the middle of its length. The strip is then strapped closely to 
the platen of the grinder^ being held firmly in position by the eccen- 
tric rolls shown in the cut. The strip is placed with the smooth side 
to the platen, leaving uppermost the rough side composed of the rubber 
backing, which is then ground off from the lining. This machine 
requires less than 1/4 horse power for its operation and is driven by a 
belt or motor drive. 



394 



RUBBER MACHIXERY 



Test Piece Geips. 

In testing rubber, one of the greatest difficulties has been to 
grip the test piece in such a way as to prevent slipping without at 
the same time injuring the rubber. Even a verv small scratch on the 
surface of a test piece is often sufficient to cause failure at that point. 

In order to prevent slipping of the test piece as its section is 
gradually reduced under increasing tension it has been found advisable 
to provide means for automatically tightening the grip. This is con- 
veniently accomplished by using a cylindrical roller mounted eccen- 
tricallv as illustrated on the left in Fio;. 410. When the rubber varies 




Fig. 410. — Test Piece Grips. 

in thickness, as is often the case, it is an advantage to use a number 
of thin cylindrical discs as illustrated on the right. These act inde- 
pendently, producing a uniform pressure over the gripping surface 
and preventing any uneven slipping. 



Testixg Devices. 
The Schoppee-Dalex Machixe. 
The tester shown in Fig. 411 is worked by hydraulic power, its 
operation, briefly stated, being as follows : The rubber test ring is 
placed over the spools and the lower spool is geared to the rack in such 
a way that it is caused to revolve during a test. This motion is trans- 
mitted to the top spool by the rubber test ring, the object of rotating 
the spools being to equalize the tension at all parts of the specimen. 
As the tension is increased the weighted lever, to the short arm of 
which the top speed is attached, is gradually deflected. When the test 
ring is broken the lever is held at the point of maximum load by 
means of a set of pawls, the breaking load being read from the 
cTfrved scale and the elongation being indicated by the verticg] scale 
just opposite the test ring. 



RUBBER LABORATORY EQUIPMENT 



395 




Fig. 411.— The Schopper-Dalen Machine. 



The Olse^^ Autogeaphic Mactiixe. 
The machine in Fig. 412 uses a test strip, i/s-inch thick. 1 inch 
wide and 6 inches long, reduced in the middle to a width of l^-inch 
for a straight length of 2 inches, on which leng-th the stretch is taken. 
Three independent tests with autographic records can be made — ten- 
sile test to rupture of the rubber, repeated load test to rupture of the 
rubber and time elono-ation test under dead load. 



396 



RUBBER MACHINERY 



A weighing system which consists of a pendulum balance in 
which the pendulum has a weighing motion of 90° — 45° either side 
of central position, obtained by use of the weight at the left end of 
the m.achine, which overcomes the gravity of the pendulum. The 
straining mechanism consists of a screw, which operates the straining 
head driven by a four to one variable speed motor, so speeds of from 




Fig. 412. — The Olsen Autographic Machine. 



6 to 24 inches per minute are readily obtained. A repeated load of 
varying amount may also be applied by operating the hand lever to the 
right of the machine. This gives a reciprocating motion to the strain- 
ing head. A quick release and hand return of the straining head is 
provided, and when dead load tests are made the head is released 
from the screw and the load applied at the extreme right end of 
machine. The rubber is gripped between two wedge rollers in each 
head which are operated simultaneously by hand levers. 

The autographic records are automatically taken and reduced so 
that four magnitudes of records may be taken, depending upon the 
stretching quality of the rubber. One curve reduces the stretch on 
the diagram 5 times; one, 10 times; one, 20 times, and one, 40 times — 
so that all tests are reduced to a standard size diagram sheet. 



RUBBER LABORATORY EQUIPMENT 



397 



The autographic time test is made bj comiectiiig the rotating 
autographic drum to the clock at the left, and thus a record is obtained 
showing the relation between time and stretch under any desired 
dead load. 

The stretch is measured from special spring clamps fitted to the 
rubber, and an exact record is obtained by the autographic fingers 
taking the measurement of elongation from these spring clamps. 




Fig. 413.— The Olsen Standard Machine, 



398 



RUBBER MACHIXERY 



The Olsex Staxdakd Machixe. 
A comparatively new machine for testing the standard form of 
tensile test specimens is illustrated in Fig. 413. It is of the pendulum 
type, arranged so the scale will wxigh in three magnitudes, either to a 
maximum of 50 pounds, 100 pounds or 200 pounds, depending on the 
grade of material to be tested. The machine is driven by a direct 
connected motor and is made with or Vvdthout attachments for measur- 
ing elongation. 

The Schwaetz Hysteresis Machix^e. 
This machine, shown in Fig. 414, extends the test piece by a 
load w^hich is increased at a given rate until either a given load or a 




Fig. 414.— The Schwartz Hysteresis Machine. 



RUBBER LABORATORY EQUIPMEXT 



399 



given extension is attained. AVhen tins point is reached tlie load is 
diminished at the given rate and the rnbber is allowed to retract. The 
relation between load and elongation is recorded by a pen. which 
draws two lines, one during extension and the other during retraction. 
What is known as the hysteresis loop made by this machine, is shown in 
Fio\ 415. This is drawn upon a sheet of paper attached to the mov- 




^^ ^ Extension C 

Fig. 415. — Hysteresis Loop. 

ing table. The line B is made during extension and is the result 
of the stretch of the rubber and of a calibrated spring. B D is the 
retraction curve. The distance D represents the sub-permanent set. 
The outlines of the curves indicate the physical properties of the rubber 
sample and thus determine its qualities and insulating values. 



The Shore Elastometer axd DuEo:\rETEE. 

An instrument suitable for measuring the hardness of soft rubber 
is un suited for hard rubber; also, one that will determine elasticity of 
soft rubber is unsuited for hard rubber. To successfully measure the 
properties named, the Elastometer for elasticity, and the Durometer 
for hardness, shown in Eig. 416, have been devised. 

The Durometer when applied to soft rubber indicates its resistance 
to the penetrating force of a blunt pin. This pin projects from the 
instrument three thirty-seconds of an inch and is held by a carefully 
calibrated spring. On the harder grades it is pushed in mo3t of its 
length against the tension of the spring. The extent of the compres- 
sion, and. converselv, the deformation of the rubber, are indicated on 



400 



BUBBER MAC HIS E BY 



the dial, expressing units of hardness. The size and position of these 
units, since the value 50 is the average hardness for soft rubber, have 
been carefully chosen and obviously will remain constant. 

In testing the elasticity of rubber with an instrument that is to 
be applied to the surface without damage, the stretch test is most 
closely imitated by one involving a tearing or cutting stress. Eubber 
having 100 per cent, elasticity will resist the penetration of a knife 
or a sharp point for a given depth without cutting in the slightest 
degree. Should, however, the elasticity be somewhat imperfect, the 
cutting will take place to the extent that the elasticity is deficient, until 



W^Sk 


rib 


m 


^^ 


^^^ 


- 


If 




■ 


:_ ^ ' 


\ -^ 




Di 


1 ej 


f^ 


'^^^^j^BB^mKjKtj^^^Sj^k 




-1 



Fig. 



-The Shore Ela5to:>ieter axd Du] 



at last the elasticity is so low at a given hardness that cutting will 
occur almost the entire distance penetrated. The Elastometer has 
been devised by applying this principle. The action is as follows : 
A medium sharp pin. three thirty-seconds of an inch long, is locked 
and caused to penetrate its entire length into the rubber. After a few 
seconds the pin is unlocked and is pushed back by the rubber, accord- 
ing to its power to recover its original form or its elasticity. The pin 
actuates a very delicately balanced indicating needle, reading in per- 
centages of elasticity. If it is pushed back only haK way. 50 per cent, 
is shown ; if all the way. as when the rubber suffers no injury at all. 
100 per cent, elasticity is shown. 



The Plasto^ietee. 
The Plastometer. shown in Fig. ill. is an instrument by which 
the quality plasticity may be indicated. Its method is direct reading 



RUBBER LABORATORY EQUIPMENT 



401 




Fig. 417. — The Plastometer. 



without injury to the material tested, i.e., unlike a ''tensile-test" in 
which the material is tested to its destruction. It has a combination 
of parts whereby a weight may be supported wholly upon a sphere, 
sufficiently hard to sustain such load without appreciable deformation, 
and means whereby the amount of penetration or indentation is deter- 
mined at the expiration of one minute. 



40: 



RUBBER MAC my FRY 



Most grades of crude rubber may be tested by the Plastometer 
in wliicli tlie sphere is a hardened steel ball, ^-inch in diameter, upon 
which is placed a weight of one kilogram, the penetration or inden- 
tation of such ball being indicated by the micrometer dial gage, indi- 
cated to one one-himdredth millimeter. Softer materials require a 
larger ball, or less weight, or both. Harder materials require a smaller 
ball, or more weight, or both. 

The Shoee Scleeoscope. 
The Shore Scleroscope. Fig. 418. records the hardness or resistance 
to penetration, as sho^^m by the height to which a small plunger ham- 




FiG. 418. — The Shore Scleroscope. 

mer will rebound. The hammer is equipped with a point so shaped that 
there is always a recoil. A scale registers the extent of the rebound 

and thus definitelv shows the relative hardness of the material tested. 



Eeasto-Dueometee. 
BreuiTs apparatus measures the elasticity and hardness of rub- 
ber. Fig. 419 is a sectional view of the device arranged for taking 
measurements of hardness. A brass tube D is screwed into the upper 
plate. In this is placed a helical spring which bears at one end on 



RUBBER LABORATORY EQUIPMENT 



403 



the base B of the shank A and at the other end on a head piece C 
which is screwed on the tube D. The shank A is graduated at its 
upper end, and this graduation serves to measure the distance by 
which the head piece C is displaced with reference to the tube D 
when one is screwed over the other. In this way the amount of pres- 
sure on the spring is measured at E, consequently, if the spring 
has been gaged the pressure which it will support is known. The 




Elasto-Durometer. 



lower end B of the shank A carries a point F which, under the pres- 
sure of the spring penetrates into the material to be tested. This base 
has a vernier index G which shows the amount of the penetration in 
tenths of a millimeter. There are, it will be seen, two characteris- 
tics of the test, the pressure and the depth to which the point is forced. 

The p. B. Dy^^amometer. 
Fig. 420 shows the P. B. Dynamometer, which consists of a solid 
cast iron table supporting the two principal parts, the apparatus pro- 



40i RUBBEli JilACHIXERY 

duciug the stresses and the appliance for measuring them. On the table 
is a horizontal spring balance which carries one of the jaws to hold 
the test piece. Means are provided to recalibrate the spring, and the 
pointer remains at the maximum indication on the breakage of a 
specimen, thus recording the breaking load. 

The load is applied either with a hand wheel and bevel gears 
for quick motion or through worm gears for heavy loads at lo^v speed. 
Pulsating stresses of any desired amplitude can be applied by an 




Fig. 420.— p. B. Dynamometer. 

eccentric gear at adjustable speeds. Samples can be tested in a bath, 
by means of which the temperature can be varied. The apparatus 
also provides for compression, plasticity, repeated bendings. wear and 
friction tests, so that it is capable of being applied to a large number of 
purposes. 

One of the important features of the 'T. B.'' system is the 
possibility of determining by its aid both the wear and tear and the 
co-efficient of friction of rubber, fabric, etc. 

The Falkexau-Sixclair Machixe. 
A machine for applying tensile tests to rubber is shown in Fig. 
421. It consists of a movable bed plate upon which is a spring balance 
and a grip for the test piece, and between them a removable wedge 
which follows up the pull on the balance and holds it at the maximum 
strain when the break occurs. The strain is applied through a screw 
by means of power or the hand wheel at the end of the machine. 



RUBBER LABORATORY EQVIPMEyT 405 

There is also a liand wheel at the side which operates a rack 
and pinion for moving the carriage rapidly to its original position 
after a test has been made. Opposite the movable grip is a fixed 
one, which, however, can be made movable bv renio"ino' a stud. In 




Fig. 421. — The Falkexau-Sixclair !\L\chixe. 

this way tests for stretch and set may be made by attaching dead 
weights to the hook by means of a cord passed over the sheave. The 
machine is also provided with a graduated scale and pointers with 
which the original reference marks on the test piece may be followed 
as the specimen is stretched, and thus the elongation be determined. 

The Claytox Machixe. 

The Clayton dynamometer gives the resistance, the elongation at 
the point of mpture, the elongation under a given burden and the 
hysteresis curve. 

The principal difference in contrast with the Schopper and the 
P. B. machines consists in the fact that Clayton's has neither spring 
nor weighted lever. 

A stream of water reaches a balanced receptacle at the rate of 
one kilo (2.2 pounds) a minute. The weight of the water, reaching 
the point gTadually, exercises traction upon the sample being tested. 
At the moment of rupture the stream of water is automatically stopped 
and the breaking load is found by weighing the amount of water in 
the receptacle. The stream can, moreover, be stopped at any time, in 
order to read off the extension under a given load. The quantity of 
water in the receptacle can also be gradually diminished. As may 
be understood, this djmamometer is remarkably easy to handle, while 
it is capable of giving results equally accurate and varied. 



406 



RUBBER MAC HI X FRY 



Ciiexeveau-Heim Recordixg- Dyxamometek. 
This machine, sho^\Ti in Fig. 422, resembles the Schopper machine 
but has a recording device F attached to the weight arm 0. Bv means 
of a gear the cylinder revolves as the weight is raised. A rack and 
pinion revolves a smaller pinion connected with the chain beside the 
cylinder. This chain carries a pencil which registers a line on the 




Fig. 422. — Cheneveau-Heim Recording Dynamo:vieter. 

cylinder. The height of the line represents the stretch, and the dis- 
tance of revolution shows the weight or pull. 

Peax of a Rec^oedixg Device. 

An anonymous author sugo-ests the apparatus shown in ±^ig. 423. 

Here it will be seen that the pendulum P swings on the center 0, 
around which a cord extends to the sample A held between the nippers. 
Attached to the nippers or holders are two pulleys around which a cord 



RUBBER LABORATORY EQUIPMENT 



407 



is stretched attached to base at one end at F , passing over pulleys at top 
and around wheel on end of registering cylinder and finally ending 
in weight G. ^ow as the specimen stretches in the jaws it is evident 
that the weight G must rise to twice the extent of the stretching of 
the sample. The movement of the sample .4, caused by the swing of 
the pendulum or weight P, will not have any effect on the length o± 
this cord which revolves the cylinder. Nor does the weight of G 
or friction of pulleys have any influence, as this pull is transferred 
to the weight G through the grips on the sample A. 

The recording pen is moved by the bar D, connected with the 
plate C, which follows out the extended end of pendulum at B, thus 




Fig. 423. — Side View of a Recording Device, 

following the movements of the weight and recording it. The weight 
E pulls the pencil out through a rack and pinion on the bar D and 
the weight pulley. 



The Hartford Rubber Testing Dynamometer. 
This machine, Fig. 424, originated at the Bureau of Standards, 
at Washington. It is specifically for rubber testing and has a capacity 
of 125 pounds. The dial is graduated in quarter pounds and the dial 
hand remains at the graduation showing the maximum strain at Mdiich 
a test piece breaks. A 36-inch scale attached to the side of the column 
enables the elongation of the test pieces to be obsen^ed. The recoil 



408 



R UBBER MA CHIXEEl 



of the springs is prevented by a cramp plate, wliicli retains tliem at 
tlie registered tension nntil returned by tlie operator. The returninii' 
device consists of two hooks, attached to the lower grip, which engage 
with pins in the upper grip when it is desired to return the dynamo- 
meter to zero. A hand wheel is attached to the worm wheel shaft for 
this purpose. 

The upper grip swivels to comj^ensate for any irreo-ularities in 
the gripping. In the steel upright is a sliding rack to the upper end of 
which is attached the lower grip. Xear the lower end of the rack 
and just above the base is the rack mechanism, driven by a motor 
attached to the base through cone pulleys having four steps, which 




Fig. 424. — The Hartford Rubber 
Testing Dynamometer. 



[G. 41 



-The Scott Testing ]\L\chine. 



RUBBER LABORATORY EQUIPMENT 409 

drive the rack and the lower grip at approximately 10, 20, 30 or 40 
inches per minute. The range of movement of the rack is 36 inches. 

An automatic knock-off guards the dynamometer from injury, 
such as might be caused by a test piece not breaking under the rated 
capacity of the instrument or while returning the lower grip to its 
normal starting position. 

The instrument is equipped with a 110 volt motor, either direct or 
60 cycle alternating current. Electric connection is made to the 
motor by an extension plug from a standard lamp socket. The motor 
is controlled by a switch on side of base. 

The instrument is 105% inches high and requires 20x14 inches 
floor space. 

The Scott Testing Machine. 

This machine, illustrated in Fig. 425, is built according to United 
States standards, on the dead weight principle. It is attached to the 
wall to avoid floor vibration and is driven by a 1/6 horse power motor. 

The head of the machine has a dial with two rows of figures. 
The outer graduations range from to 250 pounds, by pounds, and 
the inner from to 50, by fifths of pounds. One hand indicates on 
both circles the amount of stress required to break the sample. On 
the swinging lever are two weights, the upper being fixed and the 
lower removable. Delicate tests are made by removing the lower 
weight and reading the inside row of graduations on the dial. 

The test is started by means of the lever at the left, which causes 
the stretching screw to move downward at a definite speed without 
revolving. At the end of the stroke the tester automatically reverses 
and returns at high speed to its normal position, where it comes to 
rest ready to receive another sample. The pointer on the dial records 
the amount of the break and remains at that point until reset. If 
desired, the locking pawls may be held out of engagement with the 
loothed racks and an oscillating movement obtained for friction tests. 

To indicate the stretch a brass scale, graduated from to 48 
inches, is attached to the frame at the left. The scale is adjusted 
up to bring the mark to any desired point. Upon the scale are placed 
two sliding pointers, which are easily moved by hand to follow marks 
upon the sample. To the lower pointer is attached a special flexible 
tape in a round metal case which automatically winds and unwinds 
as the distance between the pointers varies. This tape gives the net 
stretch between any two marks on the sample, ^ear the tape at the 



no 



EUBUKK 



±IS±LK1 



left is SB. anfeiHDatie i^^sfcexiDg^ &r dhartbi^ device dedigned to hold 
a standaid size lelteediead mk a :Omt platen W means of two nAki^T 
ei^wered IOI1& The break and stzetch is ^ee0rde^l hi ^\ on this sheec. 
which is then plaeed in a trpewiiter to iieceire fcr-lr? I^ta f&r lecoid. 
Sercsal Te^~s —-^J te leeerded em the same diee" " z_:»nstrate Taiifr- 
tion in ~ ' san^lesu The nMymanai^ of tlii - __ liiedianisiEi 

are ain:— '. /~ n^nn whc® the s-ta^rtiiLS' le"-. : :_t ^.laeMne I* 




Ym. ^SBl- 



RUBBER LABORATORY EQUIPMENT 411 

Textile Testixg Machines. 
The textile fabrics embodied in rubber goods are designed to 
give the finished product the element of strength. Hose and belting 
are notable examples of rubber goods designed to withstand heavy 
strains in service. The element of strength is also important in such 
lines as footwear and clothing, carriage cloths, tires, and many other 
lines. As fabrics vary greatly in stretch and tensile strength test- 
ing machines are a necessity. Such tests are made on a number of 
well known machines. Test pieces previously stored so that the mois- 
ture is constant are cut with their length parallel to both warp and 
weft. These pieces are about 7 inches long and 2 inches wide. Several 
pieces are tested in each direction and about one-half of the break- 
ing load figured as the tensile value. 

Riehle Aech Powee Machixe. 
In Fig. 426 is sho^^m the Riehle '^Arch Power" testing machine. 
It has a capacity of 600 pounds pull and may be operated by either 
hand or belt power. The power mechanism consists of a worm and 
gear driven by pulleys through straight and crossed belts. A lever dis- 
engages the worm and the machine can then be operated by the hand 
wheel. The strain is measured by a standard spring balance and the 
recoil is taken up by a pair of wedges which follow the downward 
pull and prevent shock to any extent. An idle index indicates the 
maximum load or breaking strain of the specimen. 

FalivExau-Sixclaie Fabric Testixg Machine. 
The vertical form of machine as built by the Falkenau-Sinclair 
Co. (Fig. 427) is arranged for hand power operation only. The strain 
is applied to the cloth by means of worm gearing and is indicated by 
a maximum hand on the dial of a spring balance, and the recoil of 
the balance is obviated by a following up wedge, as in the ''Arch power" 
machine. The hand lever shown immediately under the dials in both 
forms of machine is for controlling the release of the spring of the 
balance when the wedge system in the rear is disengaged. For rapid 
work the worm can be thrown out of gear and the screw run up or 
down rapidly by the hand wheel. The machine is built in two sizes 
for 200 or 600 pounds capacity. 

Olsex's Fabeic Testixc^ Machine. 
The machine, illustrated in Fig. 42 S, is designed to cover the 
requirements for an automatic textile tester where accuracy, ease of 
operation and rapidity are important factors. 



412 



RUBBER MACHINERY 



The cloth is held in the heads by quick acting grips which will 
accommodate test pieces up to 3 inches wide. The machine weighs 
automatically, and the pointer remains stationary at the point on the 
scale at which the test piece breaks. The motor driven worm wheel at 
the end of the machine is for applying the load. It can also be applied 
by the hand wheel. The rack is for holding the pendulum at the 
point of rupture until returned to the starting position by the hand 
crank. 

Two machines are embodied in the one, in that the capacity may 
be readily changed from 300 pounds (1 pound increments) to 600 



r 




Fig. 427.— Falkenau-Sinclair Fabric Testing Machine. 



RUBBER LABORATORY EQUIPMENT 



413 




Fig. 428. — The Olsen Fabric Testing JMachine. 



pounds (2 pounds increments) by changing the weight of the pendu- 
lum, and on the large sized machine from 400 pounds to 1200 pounds 
capacity. 



mD-EX 



Accumulator, hydraulic, 176 

Batching ingredient, 48 
Brusher, vertical cloth, 90 
Bed plate, continuous mill, 83 
Balance-Analytic, 365 

Calender, 93 
Chaffee, 94 
doubling, 216 
doubler, Birmingham vertical, 218 

vertical, 216, 218 
even motion, 101 
engraving, 100 
feed, Ackerman, 103 

Hadfield, 105 
friction, 101 

gage. Claremont stock, 106 
horizontal doubler, 217 
leather coating, 102 
lift, hydraulic, 104 
Matthews, 101 
speeds, American, 100 

European, 100 
Steinharter, 101 
two roll vertical, 95 
three roll triangular, 98 

vertical, 96 
two speed, 97 
Calender room, Bitterlich, 136 

model plan, 134 
Cement, churn, Bridge, 245 
churn, Troester, 244 
churns, twin, Ross, 243 
measuring. Bowser, 251 
mixer, can, 242 

Berstorff, 241 

Bertram, 240 

Drew. 246 

Universal, 240 
mill. Bridge. 239 
muddler. 238 
solution, 238 
storage. Bowser, 251 
strainer, 246 

Bridge, 247 

hydraulic, 247 

screw. 247 
tube filling, Brett, 248 



Centrifuge, electric, 363 
Clutch, friction, H and B, 113 

friction, Vaughn, 114 

magnetic, 115 

Cutler-Hammer, 116, 118 
Cold curing, fabric, Bridge, 225 
Condensers, 44 

injector, 45 

surface, 45 

vacuum dryer with, 360 
Conveyor, stock, 306 

Clark. 307 

Mitchell, 306 
Cover, mixer, transparent, 69 
Cracker, 71 

double geared, 72 

two roll, 71 

washer, 13 
Crusher, rubber extraction, 258 

extractor and, Bridge, 264 
Guiguet, 265 

shrub. Bridge, 258 
De La Corte, 258 
Cutter, Circular Knife, crude rubber, 1 

scrap, Gubbins, 285 
rotary, 288 

shear. Alligator, 285 

shrub. Abbe rotary, 255 

stock. Excelsior, 192 
Holmes, 192 



Decorticator, Landolphia, Palmer, 265 
Deresination aoparatus. Chute, 272 
alkali, 272, 276 
extractors, 271, 272 
extractor, De La Fresnaye, 280 

Eves, 273 

Flamant continuous, 276 

French, 280 

German, 281 

Haddon, 278 

Lawrence, 275 
gutta-percha. 271, 278 
hardenins". Obach process, 278 
rubber, 271 
solvent, 272, 278, 280 
views on, Dr Weber, 271 
Devulcanization history, 307 



416 



IXDEX 



De\-ulcanizer, Beers, 307 
Bisas. 310 
Hall. 307 
Heller, 311 
Marks, 309 
:Mitchell, 308, 309 
Peterson, 311 
Price, 311 
Richards, 308 
Disintegrator, scrap. Gardner. 291 
Doubling-, 216 
Drier, Blower, 43 
channel, 41 

condenser and vacuum, 358 
Cumner, 316 
Dr\-ventor, 42 
fabric, coated, 208 

Parrel roll, 84 _ 

multiple cell, 85 
fan, 43 
German. 40 
rotar>-, hot air, 314. 315 

vacuum, Devine, 317 
shelf, vacuum, 39, 361, 362 
rotary, steam, 56 
Sturtevant, 42 
vacuum. Buffalo, 318 

cylindrical, 358 

oven, Frea, 359 

Scott, 319 

Stokes. 319 
Drive, Calender, 119 
calender, motor, 126 

Kelsey on, 122 
electric, 121 

calender, 126 

calender, "\\ estinghouse. 126 

motor control, 124 
three speed, 121 
two speed, 119 
variable speed, Bixby, 128 

Evans, 131 



Elasticity gage, Breuil, 402 

Shore, '399 
Extractor, Bailey-Walker. 3/ 

crusher and. Bridge. 264 

Ford. 371 

ground joint, 368 

gutta percha, Rigole, 268 
Serullas, 268 

heater, Sargent, 374 

Kemptor. 267 

Landseidl, 371 

mercurv- seal. 368 

Obach. 269 

rotary, \~alour, 267 

rubber. Lawrence, 259 

Soxhlet, 368 



Underwriter, 3/ 
Wiley, 371 



Fabric, chalking, 210 
cleaning. 210 
curing, 209 
doublinsr, 216 
finishing, dull, 212 
impregnating. 226 
inspection. 92 
measuring. S6, 87 
pasting. 209 
poHshing. 209 
printing, 212 
singeing, S8, 89 
spreading, 194 

preparation for, 84 
starching, 210 
stretching, 86 
striping. 219 

device, Guthrie. 221 

Videto. 220 
Flask, digestion, 377 
distilling. 376 
fumeless. Spy, 377 
Kjeldahl, 377 

Gage, "Ideal/' 340 
pressure, 336 

American. 336 
recording, 338 

and alarm. Edson. 340 
Bristol, 338 ^^ 
continuous 339 
precision, 339 
vacuum. Tagliabue. 337 
Grinder, roll, Bowen, 109 
Linton, 111 
scrap. Gardner. 291 
-Mitchell, 290 
Guayule. 254 

Hardness, gage, elasto-duroraeter. Bre- 
uil. 402 

durometer. Shore, 399 

plastometer, 400 

sleroscope. Shore, 402 
Heater, electric, multiple unit. 37^ 
Hydrometer, Beaume, 38S 

Xicholson, 383 

I.npregnator. Destribats. 228 
Kremer. 226 
Siverson, 227 

Joint-hammering machine. 1S6 

libber atorv- equipment. 356 
lubricator, roll, Dootson. 1C5 

Masticator. Bridge, 79 
Hancock. 77, 78 
Pointon. 81 
Troester. 82 
L^niversal, 79 



IXDEX 



41' 



^lill feed, automatic, Bragg, 74 
mechanical, 72 
Olier, 74 
Pierce, 72 
Mixer, automatic, Bragg, 7Z 
Chaffee, 59 

cover, transparent, Haubold, 69 
feed for, Pierce, 72 
hood over, 68 
mechanics, 61 
Obermaier, 77 
Olier, 74 
operation, 67 
scraper, 71 
single geared, 67 
standard, 66, 69 
three roll, Watkinson, 75 

Wicks, 76 
Molds, care of, 145 
cleaner, sandblast, 146 

brush, Plank, 145 
composition, 138 
electric deposition, 139 
machine tool list, 147 
making, 138 
matrix, 139 
metal, soft, 138 

typical, 141, 142 
Portland cement, 140 
quick curing, Eggers, 140, 141 
reforming machine, Gare, 326 
rubber, 138 

apparatus for, 144 

reforming, Hayward, 326 
tire tread and core, 142 
]\Jotors, electric, charteristics, Kelsey on. 
123 
clutch, automatic throw out, 127 
control, Kelsey on, 124 
Kelsey on, 123 
safety of, 125 

stops, 127 
peak load, reduction of, 123 

IN" aphtha, storage system, Bowser, 253 
oven, constant temperature, 359 
electric, Sargent, 362 

Plastometer, 41 

Polishing, fabric, Bridge, 209 

Press, continuous screw, 315 

double screw, 167 

gang, hydraulic. 170 

guayule block, 265 

hinged table, Perrin, 175 

knock, single screw, 165 

multiple ram, Farrell, 178 

reclaimed rubber, 324 

scrap bahng, Logeman, 285 
Sullivan, 283 

seven platen, Berstorff, 172 

single ram, hydraulic, 168 

standard screw, 166 



swan neck, hydraulic, 169 

swing table, Thropp, 176 

taper screw, 315 

three platen hydraulic, 169 

toggle joint, 167 

vulcanizer, Adamson, 171 
English, 174 
Fillingham, 171 
Shaw horizontal, 175 
Printing, fabric, Berry, 212 
Proofer, Ealter, 230 

Rushworth, 229 

single operation, 231 

two side, 231 

uniform, 231 
Pulverizer, guayule shrub. Abbe, 256 

gua3aile shrub. Williams, 254 

mineral, Kimball, 289 
Ross, 56 

rubber scrap, Gare, 289 
Pump, ^•acuum, 43 

Reclaiming waste rubber, 283 
Reclaimed rubber, conveyor, Clark, 307 
conveyor, IVIitchell, 306 
defiberizer, :\litchell, 299 
press, 324 
refining, 322, 323 

Cable calender, 324 
sheeter, Mitchell, 322 
strainer, Cowen, 321 

Royle three way, 322 
Weirs, 321 
washer, Clark, 302 

^litchell rotary, 300 
Solliday, 301 

washer-separator, Askam, 302 
Simon, 304 
Recorder, autographic, Olsen, 395, 396 
Bristol, 345 
continuous, 339 
Refiner, double gear, 70 
single gear, 69 
partitioned, "Jumbo," 71 
Regulator, pressure, 328 

pressure, Atwood-lNIorrill, 335 
Davis, 333 
H. and M.. 330 ' 
Mason, 329 
Squires, 332 

and temperature, Sarco, 334 
Tagliabue, 350 
^^"atson McDaniel, 330 
temperature, H. and M., 353 
Tagliabue, 349, 353 
Tycos, 353 
time, Tagliabue, 349 
Roll. Bestwick, 104 
Bragg, 64 
Brewster, 65 
Cowen-Bragg. 62) 
Norris, 66 



418 



INDEX 



Rubber, crude, drying systems, 33 
crude, sampling, 357 

storage, 9 

testing, 357 
cutting, 10 

power knife, 11 
drying metbods, 33 
guayule, 254 
manufacture, Esch, 34 
mixing or compounding, 59 
moisture, African, 46 

American, 46 

Asiatic, 47 
oxidation, 34, 35 
physical tests, 389 
raw, physical characteristics, 9 

treatment, 10 
sampling for analysis, 389 
solvents. 280 

shrubs, extraction of, 254 
tanks, 10 

vacuum drying, Devine, 34 
washing, 9 
waste, reforming, 325, 326 

Safety stops, 113 

brake, Dodge, 130 

gravity, Forsythe. 128 

magnetic, Cutler-Hammer. 116 

pneumatic, Birmingham, 130 

trip throw out, Farrel, 129 
Sampling rubber for analysis, 389 
Scale, automatic. 54 

counting and multiplying, 366 

estimator, manufacturers'. 367 

platform, portable, 55 
Separator, centrifugal, 363 

fiber dry, Penther, 293 

floatable. 304 

guayule, Ephraim. 263 

magnetic. Ding, 297 
Eureka, 296 
Geist. 297 
Mitchell. 296 
table, 297 

rubber and fabric. 293 

screen. Grummel, 295 
Simon. 305 

solvent, Debauge, 293 

water, continuous screw, 315 
Vaughn, 314 
Sewing machine, railway, 91 
Shear lever, hand or foot, 192 

scrao. Alligator, 285 

stock, Birmingham, 192 

tube cutting. 192 
Shell, stock, Gammeter. 108 
Shredder, rubber, crude, 12 
Sifter. Gardner. 50 

Gauntt. 49 

gyrator, 53 

reciprocating, 49 



W'erner-Pfleiderer, 51 
Signals, system, electric, 348 
Singer, gas, Curtis-Marble, 89 

oil. Granger, 88 
Solution, guide. Wood, 214 

mixer, see cement mixer 
Solvent recovery, 231 

Boeder, 235 

hood, exhaust, 237 

Heinzerling, 234 

Spence, 235 

Vincent. 232 

\\ eber-Frankenburg, 232 
Specific gravity. 381 

aoparatus, Rost, 385 

balance. Jolly, 382 
Westphale, 385 

bottle. 384 

calculation. 384, 387 

gravitometer. Young, 386 

hydrometer, Beaume, 385 
Nicholson, 383 
Spreader, bar for, Coulter. 107 

continuous, two roll, 199 

cool roll wind-up, 107 

equipment. 194 

fabric feed, Landin. 221 

fire prevention. 197 

Frankenstein-Lyst, 198 

Hancock. 194 

horizontal, English, 198 

Mann. 203 

operation, 197 

proofing both ends, 201 
Falter, 230 
Rushworth. 229 

reversible. Coulter. 107 

roll. Coulter, 223 

roller, Howkin. 206 

Rowlev-Walmslev, 199 

Salisbury, 199 

standard, 195 

steam cylinder drying, 201 

stretcher and, Birlev-^lacintosh, 203 

striping. Guthrie, 220 
Videto. 220 

varieties, 198 

vertical, Decauville, 204 
English. 206 
German, 205 
orisfin, 20 

wax, 230 

Wood-Robinson. 201 
Spreading, electrical discharge in, 197 

fabrics, preparation of, 84 

imperfections. 84 

leather. 102 

moisture. 84 

Table, cooling, 83 
Tank, defiberizing, Mitchell. 298 
softening, rubber. 10 



INDEX 



419 



Temperature alarm system, electric. 348 

control, Z27 

Tagliabue s^'stem, 349, 350 
Tycos system, 352, 353 

regulation, 327 
Testing machme, Arch-power, Riehlc 
404, 411 

autographic, Olsen, 395 

Cheneveau-Heim, 406 

Clayton, 405 

dynamometer, P. and B., 403 

Hartford, 407 

hysteresis, Schwartz, 398 

rubber, Falkenau-Sinclair, 404 

Schopper-Dalen 394 

Scott, 409 

standard, Olson, 397 

textile, 411 

Falkenau-Sinclair. 411 
Olsen, 411 
Test-piece, grinder, 393 

grips, 394 

punch press, 390 

ring, 390 

strip, 391, 392 
Thermometer, bulb, Bristol, 345 

chart, record, 347 

helical tube, Bristol, 345 

industrial, 341 

mercury cup, 343 

recording, Bristol. 344 

spiral tube, Bristol, 345 

varnish, H. and M., 345 

vulcanizer, H. and M., 342 
Trimmer, bead, Johnson, 286 
Tubing, cold cure, 191 

cut length, 189 

die, Voorhees, 186 

hand made, 179 

joint hammer, Dewe, 188 

machine made, 179 

multiple, 190 
Tubing machine, Bowley, 191 

double, Allen, 184 

drive, motor, 183 

feed for. Bridge, 186 
Kay, 184 

insulation, 180 

Royle, 181 

standard, 180 

striped, Mahoney, 184 

stock condition for, 179 

tank, soapstone, 181 

Turner, 189 

work, variety of, 180 

Valve, shut off, automatic, Tycos, 353 
reducing, Mason, 328 

Squires, 332 

Watson, McDaniel, 330 
viscosimeter, Frank, 380 

Saybolt, 378 



Vulcanizer, Bridge, Akron-Williams, 163 
continuous, Eddy, 155 
control, Ellinwood-Seiberling, 353 
door, hydraulic closing, 161 

internal lock, Allen, 164 

lock. Shaw, 163 

quick locking, Williams, 160 

self sealing. Adamson, 160 
dry heat, vertical, 150 
electric light, fabric. Burr, 223 

Riddle, 158 
fabric, VVaddington, 223 
head, boltless, WiUiams, 164 
horizontal, plain, 149 

jacketed, 150 
hot-air, French, 156 
repair, 156 
Seabury, 151 
sealing door, 159 
steam, 149 

steam separator and, Fowler, 152 
steam, vertical, 149, 152 
sulphur bath, 159 
types, general 148 
Wittenberg, 154 
Vulcanizing, cold, apparatus, 155 
cold, machine, Bridge, 225 
continuous, 154 
hot air, 156 
proofed cloth, 155 
pure gum, 159 
solar, 155 
sulphur bath, 159 
vapor, 224 



W asher, Bertram, 21 

capacitv of, 16, 18 

Day, 30 

Dessau, 25 

early forms, 31 

guayule, Lawrence. 260 

hand power, 358 

hollander, 19 

Hood, 24 

Kempster, 26 

Pointon, 28 

power for, 16, 18 

rotary, Mitchell, 300 

Solliday. 301 

Sault, 31 

separator, Askam. 302 
Koneman, 303 

sizes of, 16, 18 

sheer and, Donnelly, 29 

Smith, 30 

three roll. 17 

two roll, 13 

tub, Mitchell, 299 

Vaughn, 20 

Universal, 21 
Weighing, automatic, 57 



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Branch Office : 1011 WILLIAMSON BUILDING, CLEVELAND, OHIO 



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RUBBER MACHINERY 



CALENDERS, MILLS, REFINERS, SHEETERS, 
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BUFFALO, N. Y. 

Rubber drying is a problem which demands 
careful attention in every detail. We have de- 
signed and installed many plants and the 
general satisfaction they are giving clearly 
demonstrates the advantages obtained by using 
the Devine System. 

|r Rubber can be dried under vacuum 

lH in two hours with better results than 
1 i can possibly be 

secured by six 
wrecks of loft dry- 
ing, and it gives 
a much better 
yield than air- 

ROTARY VACUUM DRYER J^'^ J ^^^^^^ 

Devine apparatus is carefully designed for 
the special conditions to be met, and every 
part is made from the best obtainable material 
and workmanship. 

We would like to show you how we can 
save 3^ou time and money, and we can do this 
at no expense to you. We maintain a com- 
pletely equipped laboratory and if you will 
send us samples of your material, we will dr}^ 
or regenerate it and let the finished product 
speak for itself. 

Write us for our complete catalogs and 
further information on your special problems. 




ADVERTISEMEXTS 



J. p. DEVINE COMPANY 

BUFFALO, N. Y. 




VACUUM CHAMBER DRYER AND AUXILIARIES 

Our system of drying under vacuum is the result 
of over 35 years experience in the manufacture of 
Vacuum Drying Apparatus, and the apphcation of this 
apparatus to thousands of problems. This system 
assures rapid and thorough drying at low temperatures, 
saving in first cost and operating expenses, better qual- 
ity and greater uniformity of dried product, and freedom 
from climatic conditions. Small quantities of stock 
can be kept on hand, with a correspondingly small in- 
vestment. 

Our lines include Vacuum Chamber Dryers, Ro- 
tary Vacuum Dryers, Vacuum Drum Dryers, Impreg- 
nators, Vulcanizers, Deresinating Apparatus, Dry 
Vacuum Pumps, Condensers, Vacuum Pans, and com- 
plete equipment for the chemical industries. 



AD YERTISEMENTS 



Established 1836. Incorporated 1850. 

Cable Address : Liebers and 

"Bifoundry, Derby." W. U. Code. 

"Birmingham" 
Rubber Mill Machinery 

(Manufactured for over sixty consecutive years.) 

PRODUCTIVE— EFFICIENT— RELIABLE. 

Modern patterns for modern requirements. 



-3^ 




PLANT AT DERBY, CONN., U. S. A. 



Inquiries solicited for Standard or Special Machinery for 
the Rubber trade. 

Estimates and illustrations upon application. 

Alterations and repairs handled promptly. 

ENGINEERS— FOUNDERS— MACHINISTS 

BIRMINGHAM IRON FOUNDRY, 

DERBY, CONN., U. S. A. 



ADVERTISEMENTS 



"Birmingham" 
Rubber Mill Machinery. 



Crackers 


Tire Vulcanizing Presses 


Washers 


Accumulators 


Mills 


Pumps 


Refiners 


Bias Cutters 


Calenders 


Spreaders 



Hydraulic Presses — Varnishing Machines, etc., etc. 

Heavy new designs in all lines. 
Machine Moulded and Pattern Gearing, 

Spur and Herringbone Cut Gearing, 
Shafting, Pillow Blocks, Couplings, 

Friction Clutches, Pneumatic Clutches, 
Magnetic Clutches and Brakes, 

Motor Drives and Motors. 




16"x40" MILL. 

BIRMINGHAM IRON FOUNDRY 

DERBY, CONN., U. S. A. 



ADVERTISEMENTS 



' Birmingham" 
Rubber Mill Machinery 

Chilled, Sand Cast and Steel Rolls. 

Safety appliances for Mills and Line Shafts. 

Sole Builders Schofield Patent Bias Shear 

(over 100 in successful operation.) 
Asbestos Mixers and Sheeters. 
Automatic Mixing Aprons. 

Paper Wrapping Machines for tires. 
Tire Molds and Cores. 




26"x72'' 3 ROLL CALENDER 

BIRMINGHAM IRON FOUNDRY 

DERBY, CONN., U. S. A. 



AD VERTISEMENTS 



'Birraingham'' 
Rubber Mill Machinery 




74" x30' 6" Hydraulic Belt Press, 
Weight 440,000 pounds. 




Tire Vulcanizing Press, 




6^^^ Accumulatoi. 



BIRMINGHAM IRON FOUNDRY, 

DERBY, CONN., U. S. A. 



AD VERTISEMENTS 



INNER TUBE VULCANIZER. EQUIPMENT No. 600. 




We manufacture Inner Tube Vulcanizers in all 
sizes and can furnish standard or special equip- 
ment to meet your individual requirements. 



VULCANIZERS AND DEVULCANIZERS 
FOR EVERY PURPOSE. 



COMPLETE TIRE REPAIR PLANTS. 



Write for Catalog. 



The Biggs Boiler Works Co., 

AKRON, OHIO, U. S. A. 



AD YERTISEMENTS 




HORIZONTAL VULCANIZER WITH OVERHEAD 

TRACK AND TROLLEYS No. 20. 

Pioneer Manufacturers of 

VULCANIZERS for Casings, Tubes, Hose, 
Belting, Insulated Wire and various specialties. 

Jacketed Vulcanizers and Devulcanizers of every 
size and for any desired pressure. 

Let us assist in figuring your vulcanizer re- 
quirements. 

ESTABLISHED 1887. 

The Biggs Boiler Works Co., 

AKRON, OHIO, U. S. A. 



ADVERTISEMENTS 



MILLS 




Mill sizes from 6x12 to 22 and 26x84. Standard size Washers 
and Refiners. Any style of Bedplate 

CALENDERS 




Furnished in Standard and Special Combinations — Electric or Mechanical 
Safety Stops. Drive as required 

THE TURNER, VAUGHN & TAYLOR CO. 

CUYAHOGA FALLS, OHIO, U. S. A. 



AD YERTISEMENTS 



PRESSES 




----c;^ 



Hydraulic Rim Forcing Press 
for Solid Tires 




Hydraulic Presses 
Sizes 20^'' to 42^^ 



EXPERIMENTAL OUTFITS 




Laboratory Equipment — Washers, Mills, Calenders furnished singly or i" 
combinations as desired. Roll sizes 6^^x12^^ and 8^^x14^^ 

THE TURNER, VAUGHN & TAYLOR CO. 

CUYAHOGA FALLS, OHIO, U. S. A. 



AD VEBTISE2IEXTS 



The Rubber Worker's Text Book 



Probably no one will ques- 
tion the statement that the 
most widely and constantly 
used book in the rubber man- 
ufacturing trade is ''Crude 
Rubber and Compounding In- 
gredients/' The first edition 
appeared in 1899. It contained 
exactly the information that 
workers in the rubber factory, 
and particularly those engaged 
in compounding, wanted., and 
the edition was soon ex- 
hausted. A new edition was 
brought out, revised and much 
enlarged. The latest edition 
of this book — 



Crude Rubber and Compounding Ingredients 

By HENRY C. PEARSON 
Editor of The India Rubber World 

contains much new and valuable matter not found in earlier editions. 
It tells the whole story of crude rubber, its kinds, charac- 
teristics and methods of preparation for manufacture. It describes 
all the materials Avith which rubber is compounded in the process 
of converting it into manufactured goods. It discusses rubber 
substitutes and the pseudo gums, of which the number is now con- 
siderable. It omits nothing that will add to the rubber worker's 
; practical knowledge, and it is so indexed as to make reference 
-qu^ick-and easy. Many manufacturers have written that they have 
found it worth a hundred times its cost. 
A complete index sent on application. 
Price $10.00. 

THE INDIA RUBBER WORLD, 25 West 45th Street, New York 




AD YERTISEMEKTS 



The Adamson Machine Co- 

ENGINEERS, MACHINISTS 
IRON AND STEEL FOUNDERS 



AKRON, OHIO 




Builders of General Rubber Working Machinery 

Specialists in Hydraulic Presses, Quick 
Closing, Self Sealing Vulcanizers and Hydrau- 
lic Press Vulcanizers, Straining and Tubing 
Machines, Hose Molds for long hose and molds 
for any purpose. 

We have the largest equipment in the world for the 
manufacture of automobile tire molds and cores. 

We are the only builders of rubber working 
machinery and equipment operating complete Iron and 
Steel Foundries. 



AD VERTISEMENTS 



CEMENT 
Churns ^^^ Mixers 




AMERICAN TOOL & MACHINE CO., 

Incorporated 1864. BOSTON, U. S. A. 



ADVERTISEMENTS 



44 



BUFLOVAK" 

VACUUM DRYERS 

Absolutely Dries Without Injury All Kinds of 

Rubber and Compounds 




SHELF DRYER WITH VACUUM PUMP AND CONDENSER 

"Buflovak" Dryers represent *'The Highest Attainment in 
Vacuum Dryer Construction." In our Shelf Dryers, the body 
of the Dryer, even on the largest sizes, is made in one piece of our 
special '*GUN IRON" metal, thus eliminating the numerous joints 
found in other types and insuring the maintenance of a high vacuum. 

The ''Buflovak" Rotary Dryer used for drying reclaimed rubber, 
compounds, and other materials, is noted for its rigid construction, 
high efficiency, and low operating cost. Our catalog showing these 
and other Vacuum Apparatus will be sent on request. 

Buffalo Toundrv & macbine €o. 

46 Winchester Ave. BUFFALO, N. Y. 



AD TEBTISEMEXTS 



A TWO-BILLION DOLLAR RUBBER COUNTRY 




ff-ffll 





That sounds rather 
large. But during the 
last 50 years the Ama- 
zon has produced an 
average of forty mil- 
lion dollars' worth of 
rubber a year — that's 
two billion. And not 
one-tenth of its rubber 
resources has ever been 
touched. 

It is a marvelous 
country, with a future 
vastly richer than its 
past. 



The Rubber Country of the Amazon 

By HENRY C. PEARSON 
Editor of The India Rubber World 

Gives a full, truthful, delightful description of this won- 
derful country. Before writing this book the author had 
been an authoritative writer on rubber for 20 years and 
had visited every rubber-producing country on the globe. 
He went to the Amazon better equipped to describe it for 
rubber men than anyone who had preceded him. He 
stayed long, traveled leisurely, observed closely. The 
result— a most satisfying book. He describes the country, 
the rubber forests, the gatherer's life and ways — every- 
thing of interest to rubber men, and to the general reader. 

The book has 244 pages and 175 photo -illustrations, besides maps and 
charts, — a book full of information, good humor and entertainment. 

The price, including postage, is $3.00 

THE INDIA RUBBER WORLD, 25 West 45th Street, New York 



AD VEETISEMEXrS 




STEAM PLATE 




t PRESSES 



Hydraulic 

12''xl2'' to 48'^ X 144^^ with single 
or multiple cylinders and pressures 
from 40 to 1000 tons. Any number 
of plates and openings and for 
steam or gas heating. 





Knuckle Joint 

12^^x14^^ to 48'^x72'^ with pressures from 
10 to 500 tons. Any number of plates or 
openings. By hand or power. Also 
Hydraulic Power or Steam Pumps, 
Accumulators, Valves, Piping, Fittings, 
etc., etc. 



ESTABLISHED 1872 



Boomer & Boschert 
Press Co. 

336 WEST WATER STREET 
SYRACUSE, N. Y. 




ADYERTISEMEXTS 



Small Tool Specialists. 



J 



We make a specialty of Small Tools 
and Dies for use in Rubber Goods 
Factories of all kinds. 



#ljlll J Molds, Cutting Dies, 

I 1 ^C-^ ' Rollers and Stitchers, \ 

4.1pjpi / Stock Gauges, &c. &c, ^ 

Calendar Rolls Engraved 



k^ 



^ 



FOR 
SHOE SOLEING and UPPERS, 
WATER BOTTLES and the like. 



The Hoggson & Pettis Mfg. Co., 

NEW HAVEN, CONN., U. S. A. 



SPECIALISTS IN 

MOLDS for MECHANICAL 
RUBBER GOODS 

PATTERN MAKERS, MACHINISTS 

Fine Grey Iron, Hard Iron, Bronze and 
Aluminum Castings. 

PROMPT SERVICE 

McFarland Foundry and 
Machine Company 

TRENTON, N. J. 



A D VER Tl SEME NT 8 



THE LEADERSHIP 




of the Royle Perfected Tubing and Insulating 
Machines is convincingly noticeable. Every 
desirable feature for effective compound 
control has been developed to the highest 
efficiency. To this is added a general design 
of great productiveness. Use the Royle 
Perfected. 

Details are fully presented in Catalog 213. 
Write for a copy. 

JOHN ROYLE & SONS, 

Paterson, N. J., U. S. A. 

Tubing and Insulating Machines, Circular 
Looms, Strainers of voluminous output. 



AU VEBTISE21EXTS 



The Great Productive Achievement 
of this Century 






In 1900 the rubber 
plantations of the East 
covered 1750 acres, and 
produced 8233 pounds of 
rubber, w o r t h ^859. 
Xow they cover 1,500,- 
coo acres, and will pro- 
duce this year 170,000,- 
000 pounds of rubber, 
with a value of S120,- 
000,000. That is the 
most marvelous produc- 
tive development of the 
present centurv. 



What I Saw in the Tropics 

By HENRY C. PEARSON 
Editor of the India Rubber World 

tells accurately and most readably and with lavish illustration the 
story of this great plantation achievement. 

The author has been a recognized authority on rubber for 25 
years. He traveled leisurely through the rubber belt around the 
world, carefully investigating Avild rubber gathering and rubber 
cultivation everywhere, and describes what he saw in this book ; 
naturally giving most attention to the colossal plantation industry 
in the East. 

The book contains 300 pages and 200 photo illustrations. As 
a description of rubber production this book is most informing, 
and as an account of travel, exceptionally entertaining. 

Sent, postpaid, for S3.00. 

THE INDIA RUBBER WORLD, 25 West 45th Street, New York 



AD YERTISEMENTS 



Textile Machine Works 

Reading, Pa., U. S. A. 

Braided Rubber Hose is far superior to canvas wrapped 
because it is impossible for the plys to open. It will with- 
stand more pressure, it is more pliable with less tendency 
to kink and can be made in long length^. 




Our braiders have been de- 
signed specially to braid hose 
in the most approved and 
economical way, and, being- 
constructed with steel -plates 
and cut gears, the life of same, 
at a much reduced cost of 
maintenance, greatly exceeds 
that of other types of ma- 
chines and the perfect work- 
nian:diip of the machines is 
re-flecre^ in the . quality of 
the produc^^ 




ADVEEriSEMEXTS 



MECHANICAL MOLDS 



For 



Hard and Soft 
Rubber Goods 

Syringe Bag and Bottle Molds 

Molds for Rubber Toys 
Die Sinking and Steel Stamps 



THE MECHANICAL MOLD 
AND MACHINE COMPANY 



AKRON, OHIO 




The Cell Drier is used for drying 
fabric previous to impregnating. 
This machine is simple, compact, 
efficient and economical of floor 
space, power and labor. 



CEORGE A. CUTTER 

Sales Agent 

TAUNTON, - - MASS. 



"FOUR OAKS" 

Pneumatic or Compressed Air Knapsack Sprayer 



This machine is self-contained. 

**KENT'* PATTERN 

Copper Container. English made throughout 
Capacity 4 Gallons 
Working Capacity 3 Gallons 

A well-made, reliable machine 

For those li'ho prefer this type of 
machine, instead of the continuous pump- 
ing kind, this is far and azcay the best 
machine on the market. 

PRICE 67/6 

Every planter is invited to write for 
ComDlete Catalogues of "Four Oaks'' 
Spravers. which are manufactured solely 
by 

The Four Oaks Spraying Machine Co. 

FOUR OAKS WORKS 

SattOD Coldfield, Birmingham. England 

Cables: "Sprayers. Four Oaks. ' A. B. C..4th Edition 

iThe largest actual Manufacturers of Sprayers in the 

United Kingdom 



No separate pump 




AD VERTISEMENTS 



Curtis & Marble Machine Co. 

WORCESTER, MASS., 
U. S. A. 

Headquarters for 

Machinery for Handling 
Fabrics of All Kinds 
in the Rubher Trade 



BRUSHING MACHINES for cleaning 
goods before being coated; for cleaning cotton 
liners or wrappers of soapstone, talc, etc., and 
removing wrinkles; for brushing coated goods 
in connection with starch, etc.; Starching At- 
tachments; Mill Sewing Machines for stitching 
the ends of pieces together; Measuring Rolls 
and Dials; Rolling Machines; Winding Heads; 
Inspecting Machines; Guide Frames; Trade 
Marking Machines; Spot Proofing Machines; 
Winding Bars for paper tubes; Machine Brushes 
of all kinds. 



AD VERTISEMENTS 



MIXERS 



For 



RUBBER SOLUTIONS 

and COMPOUNDS 

Change Can or Pony Mixers 




No. 33 Twin Rubber Churns 



Kneaders— Doubling Machines and 

General Mixing and Grinding 

Machinery 



Chas. Ross & Son Co., 

148-156 Classon Avenue 
BROOKLYN, N. Y. 



IDVERTISE2IEKTS 



WM. R. THROPP & SONS CO. 

Rubber Mill Machinery 
and Rolls a Specialty 

TRENTON, N. J. 




TIRE TESTING MACHINE 

for testing pneumatic tires, giving a comparison test. Will test 

two 34' x4" tires at one time. 



"We manufacture all kinds of rubber mill machinery: Cal- 
enders, Grinders, Mixing Mills, Refiners, Crackers, Washers, 
Hydraulic Presses, Accumulators, Pumps, Vulcanizers, Inner Tube 
Wrappers, Rag Winders, Washer Cutters, Jar Ring Lathes, 
Tire Moulds, etc. 



ADYERTISEMEXTS 




DAY IMPERIAL MIXER. 



MIXERS FOR RUBBER. 

In any capacity from 15 to 
1200 gallons. Made with tight 
covers to prevent escape of 

solvents and steam jacketed, 
when required, for heating con- 
tents while mixing. 

Ask for our catalogs of : 
MIXERS, SIFTERS, 

RACKS, TRUCKS 
and SPECIAL EQUIPMENT 
for RUBBER MANUFAC- 
TURERS. 

The J. H. Day Company, 

Office and Factory, Cincinnati, O. 

Branches in Principal Cities. 



THE 

Beck Slitting Machines 

Are used by some of the largest 
concerns in the country, for all 
kinds of Insulation Slitting Work 

SEND FOR PRICES 

CHARLES BECK COMPANY 



609 Chestnut Street 



Philadelphia 



ADVERTISEMENTS 



Tire Making Equipment 

We have been working for the leading tire makers 
since the beginning of the industry. Our experience, 
plant and equipment is second to none. You will be 
pleased with our service. 

AKRON-WILLIAMS 

PRODUCTS, such as 

Tire Molds and Cores, 
Tire Curing Presses, 
Tire Repair Equipment, 
Tire Building Stands, 
Tube Wrapping Lathes, 
Presses, Hydraulic and Hand, 
Vulcanizing Presses, 
Vulcanizers, all kinds. 
Hose Molds and Vulcanizers 

Are well known for efficiency and ac- 
improved Tire Vulcanizing curacy In most of the tire factorles. 

Press 

Write us for Catalogue and quotations 

THE WILLIAMS FOUNDRY & MACHINE CO. 

62-66 CHERRY STREET, AKRON, OHIO 




AD VERTISEMENTS 



THE WHOLE RUBBER STORY 
EVERY MONTH 








"BUFLOVAK" 

Apparatus has won its commanding pcsilion 
VdCdum-Dn-mg of sheet and reclaimed njbl«i 

___— . ' p^wxif and othra matenafc 
■M^^ , exdusivr fralura in design 
^^^9U-i and cofHrudioa 

'BufloTak ■ ApparatBJ locides 
Buffalo Foundry & Machine Co. £- 




DUMPBLACKS ESPECIALLr FOfl ""BfE" " 



FOfl RUBBER WANUFACTUH 



How the rubber industry has 
grown ! Twenty-five years ago 
the combined capitahzation of 

the rubber factories in the 
United States did not exceed 
825,000,000. Xow it exceeds 
5450,000,000. Twenty-five years 
ago there was not a penny in- 
A'ested in rubber plantations any- 
where. Xow the rubber plan- 
tations in the Far East alone 
represent an investment of half 
a billion. And all this in a quar- 
ter centurv 



The India Rubber World 

( HENRY C. PEARSON, Editor ) 

has given each month for the last twenty-five years the news of 
this great development. It has grown with the growth of the 
trade. It has increased from -M- pages to a journal of 144 pages. 
It has a staft" of expert writers on all phases of the rubber industry. 
It has trained correspondents not only in the rubber centers of 
the United States and Europe, but in South America and the East. 
X'othing of importance escapes it. It is the most comprehensive 
and authoritative rubber publication in the world, — constantly 
increasing the knowledge of its readers and extending the market 
of its advertisers. 

Subscription in the United States and Mexico $3.00 per year; 
in all other countries $3.50. 

THE INDIA RUBBER PUBLISHING CO. 

25 West 45th Street New York 



ADVERTISEMENTS 



VULCANIZERS 




COMPLETE OUTFIT 

Model "U" 

Fori Repairing 

INNER TUBES and CASINGS 

Price $3.00 




Model "T" 

For Repairing INNER TUBES Only 

Price $2.00 



Q0% ^^ "^^^^ troubles are saved 
^^ by the use of an ADAM- 
SON VULCANIZER^^in time/' 

The simplicity of Adamson Vulcanizers 
and their very low cost, added to the IN- 
STANTLY SATISFACTORY results 
secured from their use, has gained for the 
entire line a rremendous popularity. It 
makes instant repairs anywhere, without 
trouble or danger, and at trifling expense. 
A quick, slick, permanent job — VUL- 
CANIZED, not patched. 

The ADAMSON is not an experiment, 
but the most extensively used vulcanizer 
today. Over a million motorists carry it 
in their tool kits — and they wouldn't think 
of srartmg a trip without it. It is, how- 
ever, a distmctive Vulcanizer, — unlike all 
others and protected by patents. It is so 
simple, practical, certain in its operation 
that nothmg equals it. And its price! 
It's so low that a motorist can't find an 
excuse for not buying it. It's the cheapest 
tire insurance obtainable. 



ADAMSON MANUFACTURING CO. 



Hamilton, Ontario, Canada 



East Palestine, Ohio 



AD VERTISEMEXTS 



WRAPPING 
MACHINES 

USED BY 
LEADING TIRE and 
WIRE MAKERS : : : 

PIERCE WRAPPING MACHINE CO., 

617 West Jackson Boulevard, Chicago, I11.,U. S. A. 




The Most Fascinating Problem 
in Rubber 

No one will question the statement that 
the most fascinating problem in rubber, the 
puzzle that has engaged more minds than 
any other, is the pneumatic tire — how to 
make it perfect. Thousands of inventive 
people are working on it constantly. 

The whole tire subject is of absorbing 
interest and importance. 

RUBBER TIRES 

By HENRY C. PEARSON 
Editor of The India Rubber World 

Tells the complete tire story — their history, development, method 
of construction; the different kinds and types; how they should be 
used, how cared for, how repaired. Mr. Pearson, who has edited 
THE INDIA RUBBER WORLD for 25 years, is not only an 
authority on all rubber subjects, but he has studied tire making in 
the great factories of America and Europe and has made tires him- 
self. He writes from personal knowledge. 

The tire manufacturer will find this book extremely useful; 
the dealer, repairer and user will find it invaluable. It contains 282 
pages, thoroughly indexed, and 300 illustrations. 

Price $3. 

THE INDIA RUBBER WORLD, 25 West 45tli Street, New York 



ADVERTISEMENTS 



NEW ENGLAND BUTT CO 

PROVIDENCE, R. I. 

MANUFACTURERS OF 

RUBBER 

STRIP COVERING MACHINES 



RUBBER 

SPREADING MACHINES 

RUBBER 



HOSE BRAIDERS 



Temperature Control by 

MASON 

Reducing Valves 

has proven an accurate, reliable 
method for regulating the steam 
supply to Vulcanizers, Presses, 
etc. 

Send for Catalogue 

MASON REGULATOR COMPANY 

1191 Adams Street Boston, Mass. 




ADVERTISEMENTS 



EQUIPMENT FOR 

Plantation and Wild Rubbers 

AN ESSENTIAL FACTOR in the reduction of cost 
of production is the installation of Machinery and 
transmission gear which is at once thoroughly reli- 
able, efficient, and of modern design. None have had 
more practical experience than we in designing, arrang- 
ing and supplying complete plants, including bui'dings 
and motive power, for the treatment of Plantation and 
Wild Rubbers, and our experience is at your service. 




TYPE W.R A. RUBBER MILL. 
Direct back-geared Macerating and Crepeing machine driven by means of our 
Hey wood & Bridge's Patent Friction Clutch. Arranged for direct driving 
from lineshaft. All parts of machine self-contained and above floor level. 

WRITE FOR COPY OF SECTION K3 CATALOGUE 

DAVID BRIDGE & CO., Ltd. ^^s 

Castleton, Manchester, England 



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